88 Comanche Electrical Problem

[AeroNautical]

I'll try to make this quick. I have an 88 with interior electrical problems. These components don't work: Cab lights, 12v outlets, radio, cb radio. Because they all failed at the same time I'm sure there is a common point where they are all connected to the battery, i just can't find it. All fuses have been checked, replaced and rechecked. I'd like to be able to fix it without buying a wiring harness. Any help is appreciated.

[comanche1989]

First thing I would do is check and clean grounds. What were you doing when they failed?

[87MJTIM]

Light switch!

 

All those, and then some, run through it.

[AeroNautical]

First thing I would do is check and clean grounds. What were you doing when they failed?

 

Pretty much the worse thing I could have been doing right before an electrical issue: nothing. It worked, I shut it down, and the next day it didn't work. I did nothing differently that day than any other.

[luvmyglock]

Unfortunately for you, they all run to the fuse box, then out through the firewall to the battery. Fortunately, however, they all share a ground. If memory serves me correctly, it is the P5 ground, located under the far left driver's side kickpanel. Remove the long panel above your knees, then look at the far left above the hood release. You'll see a ground there on the underside of where the panel seats. I would start by checking that ground. Good luck.

[comanchedude]

Have you tested the fuse box..you said the fuse is good so did you check that there is 12v to each fuse port? if not then you know the problem is prior to the fuse box or at the box. now if you get 12v at the fuse ports then you you know its past the fuse box. .everyone has said to check your ground..that is good advise and with the info provided may be just that. I do know the listed items are connected to the headlite switch also so that suggestion is good also. just start testing with a meter and track down were you lose power

[Biotex]

There is an 88 electrical troubleshooting manual here:

 

http://www.alpinefurniturestore.com/JeepDocumentation/jeeps.html

 

You can use the diagram to trace backwards until you find the break.

[AeroNautical]

Light switch!

 

All those, and then some, run through it.

I'll check that, it's a pain to get to though.

 

Unfortunately for you, they all run to the fuse box, then out through the firewall to the battery. Fortunately, however, they all share a ground. If memory serves me correctly, it is the P5 ground, located under the far left driver's side kickpanel. Remove the long panel above your knees, then look at the far left above the hood release. You'll see a ground there on the underside of where the panel seats. I would start by checking that ground. Good luck.

You were dead on, there was a grounding cable there. Took a minute to find it. Unfortunately, the ground makes good contact and I traced the wire, it's in good shape.

 

Have you tested the fuse box..you said the fuse is good so did you check that there is 12v to each fuse port? if not then you know the problem is prior to the fuse box or at the box. now if you get 12v at the fuse ports then you you know its past the fuse box. .everyone has said to check your ground..that is good advise and with the info provided may be just that. I do know the listed items are connected to the headlite switch also so that suggestion is good also. just start testing with a meter and track down were you lose power

There was one fuse port that didn't receive any voltage, but it was the instrument cluster, and strangely enough, they still work just fine. How it's still working is beyond me.

 

There is an 88 electrical troubleshooting manual here:

 

http://www.alpinefur...tion/jeeps.html

 

You can use the diagram to trace backwards until you find the break.

This helped quite a bit, I was bent over backwards today finding wires I had no idea where the hell they went, but the diagrams on that pdf told me exactly what they were. I do think I have narrowed it down to the battery connection, however. All grounding looks good, but none of the wires are receiving voltage.

[AeroNautical]

Well, I found the problem, and fixed it. Turns out it was a cut wire where they all intersected, almost looks like a mouse chewed through it. I would not have found it without the help of you guys tellin me to tear apart the inside of my truck, haha. As always, much appreciated. You'd never know how much a cab light can be taken for granted until you don't have one. 

[cruiser54]

Well, I found the problem, and fixed it. Turns out it was a cut wire where they all intersected, almost looks like a mouse chewed through it. I would not have found it without the help of you guys tellin me to tear apart the inside of my truck, haha. As always, much appreciated. You'd never know how much a cab light can be taken for granted until you don't have one. 

Where did you find the cut wire?

[AeroNautical]

Where did you find the cut wire?

Because alot of the electrical is aftermarket, all the wires are there, but in different places than any diagram will show. I have the guy I bought it from to thank for that, haha. The wire was placed just out of reach and sight near the headlight switch.