Co_94_PU

iTrader: (-1)

Ok on with the diagnostics..

You blew the main FL, did it actually break somewhere between the plate and that terminal (closer to the battery) or did you just get a bit of smoke?

Since you lost the main FL and not am1 or am2 the short should be somewhere between the fusible links. There are two circuits there (headlight, and horn/haz, these are the wires we see screwed to the plate in the above pic, check the resistance to grind on these.

thefishguy77

iTrader: (1)

https://www.toyotapartsdeal.com/oem/...991-35020.html

It let me add it to a cart so they "might" have it

Republic77

Hey Fishguy,
Thanks for the link.
When I entered in my truck in the "make sure it fits" section it said it doesn't.
Interesting that the part number 82991-35020 is close but has 5 digits more at the end.
I will investigate further.

Co_94_PU

iTrader: (-1)

Teaching moment!

The first part of the number tells you what is is, 82991 is a fusible link (sorry lazy and not looking up the full Toyota name)

The second part of a (full) part number -35020 tells you what it fits.

Republic77

Ahh very cool!
Thanks for that CO.
If I could buy a complete set of books for the truck I would in a heartbeat.
So
I have reconfigured the FL main,replaced (+) batt cable,(-) batt cable,changed to marine battery posts changed the FL80a fuse,
rechecked connections and leads, checked resistance on all that was suggested above,and
found no high resistance.
The only thing left was to connect a battery, and thanks to all that gave advice,
the issue seems to be solved. It is hard to say what exactly was wrong, but I think the pos batt cable was the culprit.
I was able to turn everything on at once, nothing blew up, no fire dept was involved and better yet I bumped the ignition
and my new motor kicked over ever so briefly.

Tims86Toy

I'm bringing this thread back as I may have found the actual FL for our trucks. Can anyone confirm this is the correct one? It sure looks right. After reading this thread I realized that someone had replaced mine years ago with nothing but a wire. I had a feeling when I saw this years ago that someone Jerry rigged this. I never even knew there was a FL.


https://www.megazip.net/zapchasti-dl...air-8299189101

I also found this website that has a diagram with part numbers....
https://www.megazip.net/zapchasti-dl...554566-4554566

OldBlueMidnight

Hmm, did the fusible link solve the problem for good? OP states the 80A fuse blew after installing a 140A alternator. Most high current alternators come with a kit or instructions to run an additional wire between alternator and bat, at least the one for my '85 did.

Republic77

The new fusible link did indeed fix the problem.
I have about 4500 miles on the new motor and no reoccurrence of the problem.

Tims86Toy

What gauge wire did they recommend or did you install?

OldBlueMidnight

LC sends their kit out with an 8ga wire. They don't seem to think a fuse is required on the new wire, but I put in a maxi fuse anyway,I think 80A. To be honest the whole hi-amp alternator turned into a fiasco for me. I consistently threw belts around 4500 rpm with the smaller pulley on the hi-amp alternator, so I ended up putting a stock pulley on the hi-amp unit, making it a frankenstein with unknown characteristics. Working good for now though.
https://www.lceperformance.com/High-...-p/1080005.htm

Thanks for the follow up, Republic.

Tims86Toy

You probably didn't drop too much amperage by switching to the larger OEM pulley. I work in commercial HVAC and make sheave change calculations all the time on air handler units and motors. So if you want to know about how much I can calculate the % based on the outside diameter of the sheaves/pulleys. Or you could hook up an amp meter and just measure it across the RPM curve. With the advent of LED technology I question whether a high amp alternator is needed anymore. Maybe if you had a 1990's system with huge amps and (10) 12" woofers.

thefishguy77

iTrader: (1)

Wasn't necessary in the 90's. I had a heck of a system in my 85 pickup. 2-250watt amps (I think), 2-4's and tweets, 2-6's and tweets, 2-8's, & 2-12's. Had one power cap that I installed after about 6 months. I would notice a slight dimming if I had it turned up for long periods 30+ minutes. But that was around 110db to get that issue to happen, nobody want to listen to 110db in an XtrCab Toyota for 30 minutes...