Dual batteries under the hood

BajaTaco · 07-27-2003, 10:03 PM

[EDIT 6-13-05] I added an article to my website on the dual battery system. CLICK HERE

Hey folks, I first mentioned that I was working on a dual battery setup in WATRD's thread regarding his new high-output alternator. So, this is a follow up on the progress. Get ready for a looooooooong post

OK, first a brief summary of the setup. I started out with an Optima Red Top, and I got an Optima Yellow D31T to go with it. The D31T is a "group 31" battery, so it is a bit larger than the standard Optima car batteries. I found that the D31T will fit in the stock battery location of my '98 Tacoma, with a new bracket being necessary. The clearance from the top of the posts to the underside of the hood is pretty close, but it works. I had to trim the Toyota plastic battery tray a little bit to accomodate the additional length of this battery. I got the battery with the 3/8" threaded studs so I could easily attach accessories to it. The Red Top has been relocated to the pass. side wheel well (where my QuickAir II used to be), and is still the starting battery.

Now for some more details. I decided to go with a battery combiner/isolator. After giving it some thought, I decided that a standard diode type isolator has a voltage drop that would mean a longer charging time to get my aux. battery back up to a full charge. Standard isolators have up to a .70 volt drop, so whatever your alternator usually charges the batteries up to (13.8V ?) would be dropped by that much, and take that much longer to recharge. Some people are saying that this also does not fully charge the batteries, so their respective lives are shortened. I don't know how true that is. I figured this might not be good if we drain the aux. battery at a camp, and then only want to drive a short distance before the next camp. SteveS does fine with his, so I wasn't too worried about this, but figured I would avoid the voltage drop if I could.

So, I ended up getting a 100 amp Pathmaker unit (from the makers of the Link 10, 20 battery monitors). It will automatically combine both batteries for simultaneous charging when a voltage source (alternator) is present, and disconnect them when the alternator is off, so my aux. battery cannot drain the starter battery. Additionally, it has a cutoff switch that will disconnect the batteries altogether if they begin to overcharge. All of the switch points come with factory settings, but can be user adjusted. There are LED indicators to tell what state of operation the unit is in (connected, disconnected, shut off). There is also a moment switch that will combine the batteries for an emergency start, but I probably will not use this because I don't want to burn up the contacts. (...more on this if you care to know).

Cost was a major factor (unfortunately) and all of the units I looked at without a voltage drop (xantrex pathmaker, west marine, hellroaring, etc.) were really expensive. I found a used xantrex pathmaker with a 30 day guarantee for $55 incl. shipping (it's a $179 unit new) so I figured what the heck, that's not much more than a new diode type isolator. Now that I have it, I am finding out that it might be a challenge to water-proof it. I'll probably end up making a cover for it.

Now is the time for me to mention a HUGE THANKS to Mark (crawler#976 here at Yotatech) for building the new battery housing and bracketry required for this project. Yea, I helped him, but he did most of the work and all of the welding. Last weekend we did the housing for the Red Top, and this weekend we did the new bracket for the Yellow Top.

Today, I finished prepping the brackets/hardware for paint, and painted the necessary coats throughout the day. In between coats, I worked on taking apart some of the stock wiring, and making up new cables. I used copper lugs, and 1 gauge copper cable. I put the lugs in a vice and heated them up with a torch, filled them with molten rosen-core solder, and then stuffed the cables in while it was all hot. At this point I have the two batteries installed, but I don't have the combiner/isolater mounted and hooked up. I somehow ended up short of one lug, and a big storm was on it's way through town, so I figured it was time for me to call it a day at around 5:45 pm. I took a few pics. You might see some temporary wiring floating around in these pics, but you'll get the idea. I still need to rework the mount for the cruise control actuator, which will shift a bit from it's stock location, and be closer to the air box.

This is the first time I have seen two batteries under the hood of a Tacoma, let alone one of them being a group 31 battery. I'm sure I'm not the first person to do it (dual batteries under a Taco hood), but I have never seen it myself.

PIC 1 - an overview (kinda large photo 100kb)
PIC 2 - The Red Top mounted on it's side in the new housing, and hooked up
PIC 3 - The Yellow Top in the stock battery location, with new bracket

Why am I doing all of this? See this post

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Cebby · 07-28-2003, 02:19 AM

Nice install! I didn't think it was possible to get anything as large as another battery under there. Looks great.

crawler#976 · 07-28-2003, 06:56 AM

sweet!

a little paint makes my crappy welding look pretty good!

later

***Corey*** · 07-28-2003, 07:16 AM

Look very nice Chris.
Makes me wish I had room under my hood to do a project like that.

BajaTaco · 07-28-2003, 07:49 AM

Thanks!

Lucky · 07-28-2003, 07:56 AM

This looks really good, almost stock like the optional dual battery setup on the Diesel Surfs (like mine). Interestingly on the Surfs it seems that the Dual batteries are wired in Parallel to increase the current capacity for the starter however a few people just use bigger batteries and wire one as a Leisure battery (deep Cycle) for running stuff when off road.

I presume that the Petrol engine takes more space that is why you don't see factory dual battery setups.

Only problem that it gives on the Surf is that changing the headlamp bulbs is a 40 minute job instead of a couple of minutes job.

Good job you done there.

Cheers

MNBOY · 07-28-2003, 08:37 AM

You should be very happy with the Pathmaker unit. I sell them out of my shop and have never seen one returned, which is rare in electrical equip. Very nice looking install also. I have two group 31 AGM batteries, similar to Optima blue tops, mounted in the bed, along with a starting battery under the hood. The two AGMs have the option of running accessories like the Hella lights, or they can be combined for 24 volts for the DC welder I just received (see thread in 4x4 section). I went with a West Marine combiner to charge the AGMs (I get them cheap) and have 2 gauge wire linking all the batteries through an on/off switch if I need the extra power for the winch. My installation isn't as pretty as yours, but neither is my truck. At this point I'm just going for functional. If I get to AZ this fall I'll be sure to come find you on the trails for a cold one.

Quote:

Originally posted by BajaTaco
[So, I ended up getting a 100 amp Pathmaker unit (from the makers of the Link 10, 20 battery monitors). It will automatically combine both batteries for simultaneous charging when a voltage source (alternator) is present, and disconnect them when the alternator is off, so my aux. battery cannot drain the starter battery.

This is the first time I have seen two batteries under the hood of a Tacoma, let alone one of them being a group 31 battery. I'm sure I'm not the first person to do it (dual batteries under a Taco hood), but I have never seen it myself.
]

SteveS · 07-28-2003, 08:46 AM

Chris, I still counldn't get PIC 3 to work, guess the trouble is on my end. I sure like your reason for doing this mod.

BajaTaco · 07-28-2003, 08:46 AM

Thanks Andy! Do you have the dual-batt. setup on your Surf? It must be nice to have that as a factory option! You mentioned parallel bateries, so I am assuming that they are mounted side-by-side? You could almost do that on the Tacoma, but the space isn't quite large enough to place tandem batteries.

TDiddy · 07-28-2003, 08:47 AM

I must say that's quite impressive. Nice work! I'm sure that setup will come in quite handy.

BajaTaco · 07-28-2003, 08:50 AM

Thanks Tom!!

Lucky · 07-28-2003, 09:19 AM

The batteries are mounted the same as yours, one either side. They are wired in parallel basically cos the stock batteries aren't really man enough for the starter motor on the Diesel. They are only an option mind you on the SSRX and SSRG, not available on the SSR or SSRV or SSR Limited. Wired together the provide the 700 amps plus that the starter needs.

However with an Optima Red Top and a Yellow top you get a battery that will run the Starter and one that will work as a leisure battery. I think that is really the ideal setup mind you at least with the Toyota option you can run quite a lot of electrics and still start the car OK.

Cheers

BajaTaco · 07-28-2003, 09:51 AM

Great - thanks for the info!

crawler#976 · 07-28-2003, 01:17 PM

Quote:

Originally posted by MNBOY
You should be very happy with the Pathmaker unit. I sell them out of my shop and have never seen one returned, which is rare in electrical equip............

I've got a question for ya on the unit Chris has-

Does the mounting location have to be 100% dry? After looking at the unit, I was concerned about exposing the circuit board to underhood conditions-----

later

rimpainter.com · 07-28-2003, 01:22 PM

Nice job, very professional!

4runner4ever · 07-28-2003, 01:32 PM

That's the way to go. Very good and clever setup.
Your right about the voltage drop. A normal (non-adjustable voltage) alternator will only recharge your battery up to 85-90%. And eventually shorten its life substancialy if its a lead cell bat. I'm not sure about the optima's. Wouldn't recommend it though!

BajaTaco · 07-28-2003, 02:56 PM

Quote:

Originally posted by MNBOY
You should be very happy with the Pathmaker unit. I sell them out of my shop and have never seen one returned, which is rare in electrical equip. Very nice looking install also. I have two group 31 AGM batteries, similar to Optima blue tops, mounted in the bed, along with a starting battery under the hood. The two AGMs have the option of running accessories like the Hella lights, or they can be combined for 24 volts for the DC welder I just received (see thread in 4x4 section). I went with a West Marine combiner to charge the AGMs (I get them cheap) and have 2 gauge wire linking all the batteries through an on/off switch if I need the extra power for the winch. My installation isn't as pretty as yours, but neither is my truck. At this point I'm just going for functional. If I get to AZ this fall I'll be sure to come find you on the trails for a cold one.

Whoa - weird... I never saw your post until I saw Mark quoting it. Then I went back up the thread and saw it - I guess I was writing my response to Andy when you posted. Thanks - that's good to hear about the Pathmaker. Your setup sounds POWERFUL! That sounds like a great way to go when you have a winch and a welder

NICE!!!

SteveS - yea, I like the reason too!! hehehehe

Mark - I just called Xantrex regarding the Pathmaker. They said it's not suitable for the Taco engine bay (dust/moisture). They are rated for working temps of -40F to 149F, so if I make a cover for it I might try it. Or maybe I'll just sell it and go with something else - but I really want to use it!!

Hey 96 and 4ever - thanks!!

MNBOY · 07-28-2003, 07:00 PM

Just mount the combiner in the cab and run battery cable to and from it through the firewall. I have mine mounted under the dash on the drivers side where the crappy stock speaker used to be. Works great and I can see the LEDs while I'm driving. Let me know if you have any questions on the install, I've put quite a few of them in boats.

Quote:

Originally posted by BajaTaco
Whoa - weird... I never saw your post until I saw Mark quoting it. Then I went back up the thread and saw it - I guess I was writing my response to Andy when you posted. Thanks - that's good to hear about the Pathmaker. Your setup sounds POWERFUL! That sounds like a great way to go when you have a winch and a welder NICE!!!

Mark - I just called Xantrex regarding the Pathmaker. They said it's not suitable for the Taco engine bay (dust/moisture). They are rated for working temps of -40F to 149F, so if I make a cover for it I might try it. Or maybe I'll just sell it and go with something else - but I really want to use it!!

jruz · 07-28-2003, 08:20 PM

Wow, good job. I may have to copy your setup when I finally get around to doing the dual-batt.

One quick question...where's your QuickAirII now?

I've been thinking on keeping that same spot open for a second battery...and about all I can think of for onboard air is to mount a York compressor on the lower / passenger-side of the engine.
(this all depends how the York does if it gets wet)

Or...move it to the bed of the truck...

Jim

Lucky · 07-29-2003, 10:22 AM

One thing with mounting the combiner in the cab, you will need to use really good battery cable as the resistance of the cables can be considerable. I once ran a remote battery isolator on a mini and untill I upgraded the original cables that I put in, the starter would only turn over very slowly.

Cheers

BajaTaco · 07-29-2003, 12:07 PM

Well, the jury is still out... I haven't decided yet. I was really trying to avoid putting it in the cab. I have no room left in the front around the dash, so I would have to put it in the back of the xcab. That means longer cables, which I don't want, and having high-powered cables inside the cab, which I don't want.

MNBOY, I am thinking out loud here... is there any reason I couldn't just remove the relay from the control board, and mount it in the engine compartment, and then only have to mount the circuit panel inside the cab? There are only two [EDIT: make that four] small wires connecting the circuit board to the relay. I could just replace those with heavier gauge, longer wires, and that would eliminate my problems. I could mount the control panel inside somewhere, but keep the heavy cables short, and inside the engine compartment. I don't see why this relay unit is any different than others that are mounted in an engine bay? As long as I put rubber insulators over the cable terminals, I should be ok, right?

BajaTaco · 07-29-2003, 12:12 PM

Quote:

Originally posted by jruz
Wow, good job. I may have to copy your setup when I finally get around to doing the dual-batt.

One quick question...where's your QuickAirII now?

I've been thinking on keeping that same spot open for a second battery...and about all I can think of for onboard air is to mount a York compressor on the lower / passenger-side of the engine.
(this all depends how the York does if it gets wet)

Or...move it to the bed of the truck...

Jim

My QuickAir is laying in a box right now

but I plan on mounting it in the bed, behind my toolbox (between the toolbox and the sidewall of the bed). You can see a pic of my toolbox here. I still need to see if it will fit there. If it does, I'll run a remote switch that can be reached from the back window of the camper shell (while standing outside) and plumb the air to a quick-disconnect fitting on the bumper.

MNBOY · 07-29-2003, 05:57 PM

I will have to look when I get to work tomorrow, but I can't think of why your idea wouldn't work. Most of the manufacturers warn not to shorten the wiring for the combiners, but that lengthening them is fine. I'm not sure how you have yours wired up (I'm having computer problems and can only load half of each of your pictures) but depending on the loads that will be running through each length of wire your may not need as large of wiring as you think. My combiner is wired with 12 gauge wire as I have the stock alternator and will only see a max of about 40 amps running through them, but I know the Pathmaker wires up differently than mine. Again, I'd have to see how you have your set-up wired, but I'm thinking you should be able to make it work without too much hassle.

Quote:

Originally posted by BajaTaco
Well, the jury is still out... I haven't decided yet. I was really trying to avoid putting it in the cab. I have no room left in the front around the dash, so I would have to put it in the back of the xcab. That means longer cables, which I don't want, and having high-powered cables inside the cab, which I don't want.

MNBOY, I am thinking out loud here... is there any reason I couldn't just remove the relay from the control board, and mount it in the engine compartment, and then only have to mount the circuit panel inside the cab? There are only two [EDIT: make that four] small wires connecting the circuit board to the relay. I could just replace those with heavier gauge, longer wires, and that would eliminate my problems. I could mount the control panel inside somewhere, but keep the heavy cables short, and inside the engine compartment. I don't see why this relay unit is any different than others that are mounted in an engine bay? As long as I put rubber insulators over the cable terminals, I should be ok, right?

BajaTaco · 07-29-2003, 10:02 PM

OK - some info:

I am using the stock alternator (70 amps?)

Aux. batt. (Yellow) stock neg. cable to engine block (3' or so), new 1 gauge pos. cable to isolator (7' - not hooked up yet)

Starting batt. (Red) new 1 gauge neg. cable to engine block (5'), new 1 gauge pos. cable to starter (2'), new 1 gauge pos. cable to isolator (1'-6" max - not hooked up yet)

I will also have some 10 gauge ground wire from the controller to each battery neg. terminal.

I kept the stock pos.battery cable, (which used to go from pos. terminal of Red top to starter) left it connected to the starter at one end, and connected it to the main power box lead at the other end (had a direct conn. from redtop previously)

Did I thoroughly confuse everyone?

MNBOY · 07-30-2003, 06:33 AM

I think I understand. What I was suggesting is to downsize the wiring going to and from the combiner. If you know you will never use the moment switch then the only current going through the combiner is from the alternator, which means you are wiring for about a 50 or 60 amp load max, instead of several hundred amps for the starter. You shouldn't need more than 12 gauge or 10 max, which would make an in-cab installation much easier. Use your 1 gauge cable to connect the positive terminals of the batteries through a high amperage on/off switch, so if you need both batteries together (dead starting battery, using a winch) you just need to turn the on/off switch to ON. I have mine wired this way and it works great, except that my aux batteries are mounted in the bed so the cable runs are longer than I would like. Hope this helps.

Quote:

Originally posted by BajaTaco
OK - some info:

I am using the stock alternator (70 amps?)

Aux. batt. (Yellow) stock neg. cable to engine block (3' or so), new 1 gauge pos. cable to isolator (7' - not hooked up yet)

Starting batt. (Red) new 1 gauge neg. cable to engine block (5'), new 1 gauge pos. cable to starter (2'), new 1 gauge pos. cable to isolator (1'-6" max - not hooked up yet)

I will also have some 10 gauge ground wire from the controller to each battery neg. terminal.

I kept the stock pos.battery cable, (which used to go from pos. terminal of Red top to starter) left it connected to the starter at one end, and connected it to the main power box lead at the other end (had a direct conn. from redtop previously)

Did I thoroughly confuse everyone?

07-28-2003, 02:19 AM	#2 (permalink)
Cebby Contributing Member Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 11,246	Nice install! I didn't think it was possible to get anything as large as another battery under there. Looks great. __________________ UZswap.com A site dedicated to sharing info for swapping the Toyota/ Lexus UZ (V8) engines into Toyota Trucks and 4Runners. My 4Runner 1993 4Runner, 1UZ (V8) auto dual ultimate crawler, double locked, 35's on beadlocked SR5 alloys, low lift, hacked fenders, tubbed firewall, custom armor TOOLandFAB.com A discussion forum dedicated to tools, fabrication & workshops. See my JD2 Bender Hydro Conversion BUY THIS 2008 CALENDAR

07-28-2003, 07:16 AM	#4 (permalink)
*Corey* Co-Founder/Administrator Staff Join Date: May 2002 Location: Auburn, Washington Posts: 26,076	Look very nice Chris. Makes me wish I had room under my hood to do a project like that. __________________ Corey 2007 FJ Cruiser Built for 4wheelin', expedition, camping, and overlanding use PNW FJ Cruisers ☺ Detailing 101 ☺ Join Topsites ☺ Muffler Comparisons ☺ Maggiolinas In The Wild FJ Cruiser Buildup ☺ New Roof Top Tent ☺ Video Of My Penthouse Part II ☺ Rehinge Your ARB/Engel Fridge Blog About Roof Top Tents ☺ FJC Magazines Online Review Of My Tent ☺ 2009 Specialized Rockhopper Pro

07-28-2003, 07:49 AM	#5 (permalink)
BajaTaco Contributing Member Join Date: Nov 2002 Location: Prescott, AZ Posts: 644	Thanks! __________________ Chris Marzonie BAJATACO.COM Toyota light expedition vehicle Adventure reports Lots of Photos OVERLAND JOURNAL North America's first vehicle-dependent expedition magazine

07-28-2003, 07:56 AM	#6 (permalink)
Lucky Contributing Member Join Date: Mar 2003 Location: Hemel Hempstead, UK Posts: 88	This looks really good, almost stock like the optional dual battery setup on the Diesel Surfs (like mine). Interestingly on the Surfs it seems that the Dual batteries are wired in Parallel to increase the current capacity for the starter however a few people just use bigger batteries and wire one as a Leisure battery (deep Cycle) for running stuff when off road. I presume that the Petrol engine takes more space that is why you don't see factory dual battery setups. Only problem that it gives on the Surf is that changing the headlamp bulbs is a 40 minute job instead of a couple of minutes job. Good job you done there. Cheers __________________ Andy 1993 Toyota Hilux Surf (Japanese 4 Runner), 2.4 Turbo Diesel, Custom flush mount rear fog lamps, Ring front fogs and spots, Thule Roof Rack, Arrigoni and De Angelis roof rails, Sony Double DIN stereo, IPAQ GPS system.

07-28-2003, 08:46 AM	#9 (permalink)
BajaTaco Contributing Member Join Date: Nov 2002 Location: Prescott, AZ Posts: 644	Thanks Andy! Do you have the dual-batt. setup on your Surf? It must be nice to have that as a factory option! You mentioned parallel bateries, so I am assuming that they are mounted side-by-side? You could almost do that on the Tacoma, but the space isn't quite large enough to place tandem batteries. __________________ Chris Marzonie BAJATACO.COM Toyota light expedition vehicle Adventure reports Lots of Photos OVERLAND JOURNAL North America's first vehicle-dependent expedition magazine

07-28-2003, 06:56 AM	#3 (permalink)
crawler#976 Registered User Join Date: Apr 2003 Location: Chino Valley, Az. Posts: 938	sweet! a little paint makes my crappy welding look pretty good! later

07-28-2003, 08:46 AM	#8 (permalink)
SteveS Registered User Join Date: Jan 2003 Location: Long Beach Posts: 106	Chris, I still counldn't get PIC 3 to work, guess the trouble is on my end. I sure like your reason for doing this mod.

07-28-2003, 08:47 AM	#10 (permalink)
TDiddy Contributing Member Join Date: Sep 2002 Location: Urbandale, IA Posts: 7,113	I must say that's quite impressive. Nice work! I'm sure that setup will come in quite handy.

07-28-2003, 08:50 AM	#11 (permalink)
BajaTaco Contributing Member Join Date: Nov 2002 Location: Prescott, AZ Posts: 644	Thanks Tom!! __________________ Chris Marzonie BAJATACO.COM Toyota light expedition vehicle Adventure reports Lots of Photos OVERLAND JOURNAL North America's first vehicle-dependent expedition magazine

07-28-2003, 09:19 AM	#12 (permalink)
Lucky Contributing Member Join Date: Mar 2003 Location: Hemel Hempstead, UK Posts: 88	The batteries are mounted the same as yours, one either side. They are wired in parallel basically cos the stock batteries aren't really man enough for the starter motor on the Diesel. They are only an option mind you on the SSRX and SSRG, not available on the SSR or SSRV or SSR Limited. Wired together the provide the 700 amps plus that the starter needs. However with an Optima Red Top and a Yellow top you get a battery that will run the Starter and one that will work as a leisure battery. I think that is really the ideal setup mind you at least with the Toyota option you can run quite a lot of electrics and still start the car OK. Cheers __________________ Andy 1993 Toyota Hilux Surf (Japanese 4 Runner), 2.4 Turbo Diesel, Custom flush mount rear fog lamps, Ring front fogs and spots, Thule Roof Rack, Arrigoni and De Angelis roof rails, Sony Double DIN stereo, IPAQ GPS system.

07-28-2003, 09:51 AM	#13 (permalink)
BajaTaco Contributing Member Join Date: Nov 2002 Location: Prescott, AZ Posts: 644	Great - thanks for the info! __________________ Chris Marzonie BAJATACO.COM Toyota light expedition vehicle Adventure reports Lots of Photos OVERLAND JOURNAL North America's first vehicle-dependent expedition magazine

07-28-2003, 01:22 PM	#15 (permalink)
rimpainter.com Contributing Member Join Date: Jan 2003 Posts: 10,797	Nice job, very professional! __________________ www.rimpainter.com Get your O Gasket Mod Here! My SC'd 4Runner's Profile My YouTube vids

07-28-2003, 01:32 PM	#16 (permalink)
4runner4ever Contributing Member Join Date: May 2003 Location: the Netherlands Posts: 408	That's the way to go. Very good and clever setup. Your right about the voltage drop. A normal (non-adjustable voltage) alternator will only recharge your battery up to 85-90%. And eventually shorten its life substancialy if its a lead cell bat. I'm not sure about the optima's. Wouldn't recommend it though! __________________ '90 4R 2JZ-GE swap, headers, turbo and intercooler FR and RR LC axles coils and discs all around AllPro parking brake 305/70 R16 Yokohama MT 4.88 gears

07-28-2003, 08:20 PM	#19 (permalink)
jruz Guest Join Date: Oct 2002 Location: North Bend, WA Posts: 1,093	Wow, good job. I may have to copy your setup when I finally get around to doing the dual-batt. One quick question...where's your QuickAirII now? I've been thinking on keeping that same spot open for a second battery...and about all I can think of for onboard air is to mount a York compressor on the lower / passenger-side of the engine. (this all depends how the York does if it gets wet) Or...move it to the bed of the truck... Jim

07-29-2003, 10:22 AM	#20 (permalink)
Lucky Contributing Member Join Date: Mar 2003 Location: Hemel Hempstead, UK Posts: 88	One thing with mounting the combiner in the cab, you will need to use really good battery cable as the resistance of the cables can be considerable. I once ran a remote battery isolator on a mini and untill I upgraded the original cables that I put in, the starter would only turn over very slowly. Cheers __________________ Andy 1993 Toyota Hilux Surf (Japanese 4 Runner), 2.4 Turbo Diesel, Custom flush mount rear fog lamps, Ring front fogs and spots, Thule Roof Rack, Arrigoni and De Angelis roof rails, Sony Double DIN stereo, IPAQ GPS system.

07-29-2003, 12:07 PM	#21 (permalink)
BajaTaco Contributing Member Join Date: Nov 2002 Location: Prescott, AZ Posts: 644	Well, the jury is still out... I haven't decided yet. I was really trying to avoid putting it in the cab. I have no room left in the front around the dash, so I would have to put it in the back of the xcab. That means longer cables, which I don't want, and having high-powered cables inside the cab, which I don't want. MNBOY, I am thinking out loud here... is there any reason I couldn't just remove the relay from the control board, and mount it in the engine compartment, and then only have to mount the circuit panel inside the cab? There are only two [EDIT: make that four] small wires connecting the circuit board to the relay. I could just replace those with heavier gauge, longer wires, and that would eliminate my problems. I could mount the control panel inside somewhere, but keep the heavy cables short, and inside the engine compartment. I don't see why this relay unit is any different than others that are mounted in an engine bay? As long as I put rubber insulators over the cable terminals, I should be ok, right? __________________ Chris Marzonie BAJATACO.COM Toyota light expedition vehicle Adventure reports Lots of Photos OVERLAND JOURNAL North America's first vehicle-dependent expedition magazine Last edited by BajaTaco; 07-29-2003 at 02:41 PM.

07-29-2003, 10:02 PM	#24 (permalink)
BajaTaco Contributing Member Join Date: Nov 2002 Location: Prescott, AZ Posts: 644	OK - some info: I am using the stock alternator (70 amps?) Aux. batt. (Yellow) stock neg. cable to engine block (3' or so), new 1 gauge pos. cable to isolator (7' - not hooked up yet) Starting batt. (Red) new 1 gauge neg. cable to engine block (5'), new 1 gauge pos. cable to starter (2'), new 1 gauge pos. cable to isolator (1'-6" max - not hooked up yet) I will also have some 10 gauge ground wire from the controller to each battery neg. terminal. I kept the stock pos.battery cable, (which used to go from pos. terminal of Red top to starter) left it connected to the starter at one end, and connected it to the main power box lead at the other end (had a direct conn. from redtop previously) Did I thoroughly confuse everyone? __________________ Chris Marzonie BAJATACO.COM Toyota light expedition vehicle Adventure reports Lots of Photos OVERLAND JOURNAL North America's first vehicle-dependent expedition magazine Last edited by BajaTaco; 07-29-2003 at 10:04 PM.

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