Electical issue: No dash light up, won't crank

Okay Im at my wits end.

I have 95 SX Single cab truck V6 manual.

My issue is if you turn the key nothing happens. Literally. The dash doesn't light up, won't crank, nothing. This just happened suddenly after driving it home from work the day before.

The key dinger doesn't even stop and acts like it thinks the key is in the off position still.

Here is all that I have done:

1) New battery just last month, just got it tested today to double check, its fine.

2) Yes I've tried jumping it too with my other truck

3) Removed and cleaned ALL grounds in the engine bay, none of them were corroded though. After cleaned one of them(ECU ground under intake) the dash did light up. But then went out. Then after sitting for 5 seconds, slowly lit back up, wouldn't crank though. Then nothing. YOu'd think it would be a ground issue from this, alas, fiddling with grounds hasn't done anything or made it light back up.

4) tore apart the column think the ignition switch was fucked up. I pulled it apart, didn't look bad, cleaned it, reinstalled, no change.

5) have pulled every fuse and relay to reseat connections, again, nothing is corroded. Popped open relays to check them, again, fine. And pulled apart both fuse boxes to check for corrosion, again, nothing.

6) I ran my battery cables around the truck connected to the ground terminal in hopes it would provide a better ground and work. Nothing changed though.





I am measuring a voltage drop into the cab somehow. Im doing this by sticking the positive probe into the fuse box in the cab, doesn't seem to matter which fuse I check, get around 4-6v. If i run the positive probe to the batter but keep the neg on in the same spot in the cab, i get 12.5v. I don't know how this is happening.

Main fuse box measures fine.



Before I spend a lot of money on all new wiring from the battery to the starter and such plus maybe a new ignition switch. Any suggestions?






I do NOT have ANY aftermarket electrical accessories(lights and stuff) on this truck, not even a trailer harness.

 

I had the same symptoms, voltage in the cab was 3.5... everywhere up to the the fuse box was a solid 12.6. Ended up being a small missing bolt that holds the AM2 fuse to the buss bar in the fuse box. https://www.tacomaworld.com/threads...way-to-work-fixed.539965/page-3#post-17471720

 

Door is open when this happens. Basically if you have the door open and you turn the key to on the dinger slows in pace then turns off. Mine doesn't. Just keeps dinging away as if the key isn't on.

Thanks! I just read through the thread. I check that buss bar but I will at least check that area again. Seems like a similar situation.

 

Well I check my am2 fuse. Broke the top off trying to pull it. But touching the fuse element shows 12.5v

Damn

 

got it!

The alt fuse was it. Idk why. But I just pressed on it a bit and Bam. All good.

Going to order a new alt fuse and am2 one as well.

Thanks!

 

Awesome man, thanks for reporting back so quick when you found it. Saved me from typing some long ass response for a problem that's already fixed

 

Hmm this doesn't look good.



Little melting has happened at some point.

Can't get the fuse out and that bolt just spins doesn't come out.

That's a problem.

 

Hmm so can someone confirm this.

This wire was bolted to the bus bar on the side of the fuse box.



However this wire goes straight to the positive terminal on the battery. Which doesn't make much sense to me if it's supposed to be fusing the alternator which comes in on the main wire attached via a stud in the fuse box.

This would by pass the fuse. Which is weird. And means I shouldn't have had this issue really.

The connector looks oem so it must have gone somewhere. Any idea where originally?

My 2003 has it going right to the battery too..

 

This rings a bell and is OEM I think. The fuse box gets power direct from both the battery and the alt or something weird like that.

For some reason this memory is coming at me from back when we were doing the GM Alt mod because we wired the alt direct to the battery.

That's all I got.

 

well it must be how its supposed to be. It doesn't make a lot of sense to me...but how Igor is wired.

Im trying to figure out if I can de pin the fuse box and buy a replacement because I can't get the alt fuse out due to the bolt having melted the plastic won't fully unthread.

 

That was part of what triggered the memory for me. Not being able to disconnect that wire. That has happened before somewhere but I can't remember the context. Have you looked at the FSM? I wonder what it shows.

@Speedytech7

 

Nah I get the wire off.

If the fuse. The bolt on the inside that I took photos of above. It melted the plastic so the captive metal sleeve that was keyed to the plastic just spins. It's corroded so won't come loose.

I figured out how to depin the fuse box so just going to replace it.

 

If you can get the fuse out send me pictures. I fix damaged electrical stuff all time. If the plastic mold is deformed there’s other ways around that too. If you would like my advice it’ll be here.

 

Well the beat photos I have are up above. Put it back together in the hopes I could drive it. But won't work again. I suspect it's because I loosed the contact even more trying to get it loose.

The bushing on the inside is spinning. I'm sure if I filled it with some contact cement or something similar it would hold it enough. Might try that at least first.

 

I wouldn’t spend too much time trying to get contact cement to bite. You can remove the actual fuse block from the exterior mold. There’s two tabs on alternate sides that you push to the Side and you can pull it out. It’s a pain in the ass to do but you can. One option you have is you cut the loose nut that spins off and use a bolt and nut on the backside. You’ll want to use a bolt that’s just the right length. You don’t want more bolt that you need. Any metal to metal contact on that bus will conduct just fine.

If the issue you’re having is at the fuse you’ll need to remove the fuse block still and use a similar method. It looks as if it sustained some over heat. I wouldn’t doubt if the loose wire created a space which allowed for arcing. This probably happened on the input side of the fuse which is why the fuse didn’t blow it just melted everything around that.

 

No no.

I already pealed it all apart. Not that bad really.

Its not a "nut" on the backside of the bolt that holds the fuse in. Its a round threaded cylinder that was keyed to the plastic. But now the plastic melted so it just spins. I have no way to grab it and stop it from spinning due to space constraints. I tried shoving a couple screw drivers in there but no dice.

The epoxy could potentially rebond the the cylinder to the fuse box and allow me to pull the bolt and clean it then re tighten it. This would be temporay as I still plan on replacing the whole fuse box.

When I take it apart again I'll post photos of what is going on tomorrow.


but that is a good thinking way of how it melted. Makes me feel a bit better at least haha

 

Ok 10-4 I’m with you now. If you send me a picture so I know how much space you have to work with I’ll have a better idea. I’ve done a bunch of plastic repair and they sell this stuff called plastic weld that works really well.