MTL_4runner

I was reading this morning and found this:

95 4Runner V6 with electrical problem. I have seen a common problem that has eluded me in finding the actual cause. Customers will complain that at times or many times when stepping on the brake the radio will cut out and the lights may dim then return to normal. Some have had the engine stall, which creates and I agree a safety problem. I have been able to duplicate the condition on some models. Until recently the Tech line has chose to ignore the condition but it turns out that the Lexus line has had the same problem. The funny thing is that only the 95 4Runner Limited with the 3.0 and loaded model is affected. I always knew that a ground somewhere was the cause. They are saying that cleaning the negative battery cable at the battery and to ground from the battery is needed (clean down the paint where it bolts to the vehicle). Add a ground wire from the negative battery connection to the inner fender. 4/99. Update: Still some sensitivity with the load showing up when the radio cuts out for an instant then comes right back on. Ground improved the general running but the problem is not totally eliminated but greatly reduced. 6/99 More updates from Pat in Atlanta: On the 95 4Runner with electrical problems topic, I have fixed many of these vehicles by increasing the size of the power feed from the battery to the main slow blow fuse. It seems that the wire heats up and causes a voltage drop in the system sometimes causing the EFI system to shut down. Thanks Pat 5/00

Got this off of Yotarepair.com and thought it might help someone with a 2nd gen out there.

Sbrut95

Oh my God, thank you so much for this. Mine has been doing this for over a month and the guys at Mobile Music had no clue. EIther did I. So cleaning the Terminal and checking the spot where it is grounded may help huh. Dang, if you hear anything else on this please post it. Thanks again, I will have to try this as soon as I can. My check engine light came on today too, I dont know if this could have anything to do with that, but it could be.

MTL_4runner

It seemed like the last part was the actual fix, but making sure the ground is good is also very important.

On the 95 4Runner with electrical problems topic, I have fixed many of these vehicles by increasing the size of the power feed from the battery to the main slow blow fuse. It seems that the wire heats up and causes a voltage drop in the system sometimes causing the EFI system to shut down.

Sbrut95

MTL-

I hate to go off an a tangent about my vehicle but do you have any idea if this exact thing were happening to my car, including the problem with EFI. Could that trigger my Check Engine light? Im wondering if this is why I feel hesitation while in fifth gear and try to accelerate? Maybe the problem made my Check engine light come on? I guess the only way to find out is to reground the battery and clean up the terminals and see what happens. would the Check engine light turn off auto. or is there something that has to be done to get that thing to shut off?

MTL_4runner

They could be related but without pulling the codes, I have no idea.
With a hesitation it sounds like a TPS but you really needs those codes to ell anything.

You can pull the codes yourself here:
http://www.off-road.com/toyota/tech/codes/index.html

Then post what you get and we can go from there.
Just pull the negative battery terminal for 5 min will reset the engine light.

anthony1

iTrader: (1)

I had similar problem before. Replaced with Optima Batt...no problem since.

Fink

Lucky for me I don't have the Limited model so I've never had that problem before...except when I left my system on for about 10 minutes and then tried to start my car...if I hit the brakes the whole car would go dark. Thank god for jumper cables!

Fink

Dluvr22

Ive been having the samre problem for over a year. Whenever I hit the brakes , my battery gauge in the dash shows a significant voltage drop.. This gets worse when the headights are on at night. I switched to an optima red top about 6 months ago and the problem wasn't so bad but it is rearing its ugly head lately. Ieven thought a needed a new altenator but when the guys checked it at a repair facility they said it was fine.I'm going to try what you suggested MTL and hope it works.

ROMAD

I am having this exact same problem on the exact same vehicle (95/3.0/AT) as well and it is driving me nuts! I have been chasing down every ground wire, relay and connection I can find - nothing has made it better.

Does any one know exactly where the "slow burn fuse" is located? I want to try this fix but I can not find this "slow burn fuse"....nothing in Haynes or Chiltons.

Any good descriptions or pics would be greatly appreciated...I have got to fix this one.

Thanks for any feedback!

Sbrut95

I havnt been having the problem any more. ALl I did was scratch the paint away where the ground wire went to the metal. It still had paint on it and wasnt right up agains the metal. Everything seems to be good now, knock on wood.

ROMAD

Are you talking about the ground wire that connects to the (-) Terminal and goes right to the body? this is about a 6-8" wire and a Phillips connector if my memory is right (4Runnner is out in the parking lot right now..)

I am about to go to lunch and I will sand this one down to bare metal and see if that helps any. Thanks for the feed back!

Any idea on the "slow blow fuse" - gotta be a fuse-able link somewhere but I don't know which one is the main one or where it is actually located

Sbrut95

I dont know about the slow blow fuse but I would definitely try the ground wire from the - terminal on your battery. Yeah, its the one thats about 6 in. long and connects right to the side of the body. Try that out. Thats all I did.

ROMAD

Well, I sanded the connection point down to shiny bare metal on both the connector and the body during my lunch break (it was a 10mm bolt not a Phillips as stated by me above).


No luck for me...same problems exist: brake lights make the voltage drop momentarily, flash to pass high beams damn near stall the truck out while driving (thats a fun one to find out about @ 70MPH) I even have a tiny bit of alternator whine with the fan on (doesn't matter if AC is on or not)...There is a occasional clicking from the Automatic shifter lockout relay thing inside the center console as well...it works fine but just randomly clicks away some times.

WTF?? Everything is stock and un modified with 88K and just sorta started one day about a month ago. This is killing me
Thanks for the input so far - maybe someone else has an idea on this one?

MTL_4runner

I believe the slow blow fuse is the main fuse for the fusebox panel.
So try running another decent gage wire from the + on the battery to the fuse panel main.
See if that helps at all.

Sbrut95

[QUOTE=ROMAD]Well, I sanded the connection point down to shiny bare metal on both the connector and the body during my lunch break (it was a 10mm bolt not a Phillips as stated by me above).


No luck for me...same problems exist: brake lights make the voltage drop momentarily, flash to pass high beams damn near stall the truck out while driving (thats a fun one to find out about @ 70MPH) I even have a tiny bit of alternator whine with the fan on (doesn't matter if AC is on or not)...There is a occasional clicking from the Automatic shifter lockout relay thing inside the center console as well...it works fine but just randomly clicks away some times.

WTF?? Everything is stock and un modified with 88K and just sorta started one day about a month ago. This is killing me
Thanks for the input so far - maybe someone else has an idea on this one?


Sorry man, that sucks. Try the + wire thingy too. I cant figure out why mine is back to normal, but let me tell you, it is nice not having the stereo cut out on you every 5 seconds. Good luck finding the problem! I know how you feel.

ROMAD

Well - I fixed it.

I should have caught this much much sooner but alas - I missed the obvious. I started troubleshooting the higher, more complex layers first instead of doing what I knew.
Always, *always* troubleshoot the physical layer first!

I was looking into bad relays, shorts and ghost problems when I should have been looking at the obvious to start with. I assumed too much. Quick 'back story' first before the fix. The 4Runner is 'new to me' 2 months ago with 86K. I bought it from a airline pilot who took good care of it and had receipts to prove it + carfax and the $100 dealership check showed it to be free of major problems except a dirty air cleaner and broken power antenna. Once the problem started I had the battery and alternator checked (in the vehicle) at Autozone with a tester hooked to the +/- on the battery loaded and unloaded and was told all was fine...then I went down the mystery path of shotgun troubleshooting - and I knew better

After talking to mechanics all over the place and searching the web far and wide - this post was as close as I got to the problem. I did the cleanup of the neg. wires with no avail and the frustration continued. After re-reading the above posts one thing stood out - "I had similar problem before. Replaced with Optima Batt...no problem since."

I know Optima's are good batteries but they are not a magical cureall for electrical problems. None the less it fixed the problem for at least one guy...my battery had already 'tested' OK and the terminals were cleaned many times over by me. I also found a nugget of info on Yotarepair.com that made mention of Sears batteries (which I had inherited from the previous owner - and it had 'tested' fine) being particularly venerable to weak cells;etc.

So I popped the caps on my "tested: good" battery. OMG the cells were damn near DRY!! all 6 of them!! I poured a liter of water into the battery before they were full <sigh> instantly things improved - not fixed at all but they did get better. That was enough for me. I missed the obvious :pat: THE BATTERY WAS SHOT!! its amazing it even worked at all really...dont ask me how it tested OK at Autozone

SO a quick stop at my local SAMS for a Optima Blue top starter/deep cycle battery ($110 installed) and everything was better...lights don't flicker with the brake pedal, flash-to-pass doesn't stall the 4Runner, radio doesn't whine and it starts in 0.5 seconds cold now Lights are brighter and I swear in runs better (amazing what 12v does for EFI huh? ) it all seems so obvious now

Sorry for the long post but I felt it worth while. I missed the obvious and suffered because of it. Maybe somebody else will find this post while searching and realize their problems sooner than I did.

Many, many thanks to those that stopped to help and offer a word or two. Thank you.

Sbrut95

NICE!