Chasing those ELECTRICAL GREMLINS

[GIT-R-DONE]

For those of you that know, I am restoring a 91 truck. I had to change the cab for the rust factor. All has gone good so far . . until tonite. I used the same wiring harness and dash. Currently, truck will start up, and I have power to all fuses in the fuse box. BUT, I have no windshield wipers, cargo light, heater blower, or radio. So, there is power to the fuses for the things that arent working. . . they just dont work.



The gauges seem to be working, at least the way they were before with a fluctuation of amp gauge and oil pressure gauge. It would appear that there is a ground missing somewhere, but I have no idea as to where.



I took my time as I went through the truck putting it together, making sure that any ground wire I came across, I made bare metal contact and secured it the best I could, knowing that these are critical for things to work properly.



Is there a cab ground or some other ground that is so obvious that I am missing, or has anyone else ever run into something like this before?

 

[TWorline]

Grab your jumper cables and hook 1 end to your battery and the other end to your cab and see if they work. If they work run a ground from your engine to your cab. If we wern't in the middle of a blizzard right now I would go out & check to see if there is a ground between the engine and the cab, unless you want me to.

 

[GIT-R-DONE]

Any help is appreciated. I did run a ground strap fromt the crossmember behind the cab. . to the cab. Didnt change anything. Seems weird that if I turn on the park lights, then turn the key on, park goes out. After I did that for a while, then it started working ok and the park stayed on.



I didnt really have time today to work on the electrical. Bled the brakes today along with putting the interior back together, and doing exhaust. If I have to, I will put everything on a toggle switch and run a seperate fuse box. Just seems funny, form the radio over to passenger side, nothing works. I still think its a ground somewhere, but am open to other ideas here.



Might have a chance to look a little further tomorrow.

 

[Philip]

Did you hook the dash grounds up behind the cargo light switch?

 

[GIT-R-DONE]

Yes, there were actually 3 ground wires there. One for the radio and 2 others, I dont know what they were for or where they go. . . but they were hooked up as well.

 

[Philip]

One is for the radio. One is for the dash cluster. The other is the message center.



That is the only cab grounds I have found.



Did you try the jumper cable trick like TWorline asked?



Going from the frame to the cab with a ground cable means very little. The engine is the main ground. The body ground for the frame is a 10ga wire off the negative battery cable. Engine and trans mounts are rubber. If you get a ground threw them you are lucky. Thats why TW suggested it.

 

[GIT-R-DONE]

Well, I think I found something. I put some jumpers on the heater blower to make sure it worked. It did work. So, I rip the dash apart and with a test light, find that sometimes it works and sometimes doesnt.



Now, I put a test light to the power wire that goes to the heater contol switch, and found that there is a spot in the steering wheel when I turn it ever so slowly, that cuts the power to the heater blower and also makes some of the gauges act erractic. So, I think I may have found the problem.



One of Dodges better ideas, so you cant pull the ignition switch out, or pull the turn signal harness out. . . they put a 20 Torx bit screw that has a pin in the center of the screw. I dont have anything like that for a tool. I tried drilling out the center of the bit, but with no luck. They must be hardened steel and with such a tiny bit. . . . SO... .



Does anyone make a torx bit with the center of the bit having a hole in it? Never saw one before but I NEED ONE... .



Anyway, at least I know where the problem is, now I just have to get the right tools to rip it apart to find out what is grounding it out when the wheel is turned. Could the ignition switch cause someting like this?

 

[dodgenstein]

The bit you need is called a "tamper proof " Torx bit. You should be able to get one at an auto parts place, or a tool truck,maybe even Sears. Sometimes you can take a small punch and break the pin out and use a regular Torx bit.

 

[TWorline]

A simple way to get around the tamperproof screws is put a straight slot in it with a dremel tool and a cutoff wheel then use a straight blade screwdriver to take it out. I used to do car audio stuff, another tip for you guys having ground problems is to put a star washer between the body and your terminal then tighten it down, the star washer grips the metal of the body and the terminal. Also keeps the terminal from wrapping around the screw while you tighten it.

 

[GIT-R-DONE]

Grab your jumper cables and hook 1 end to your battery and the other end to your cab and see if they work. If they work run a ground from your engine to your cab. If we wern't in the middle of a blizzard right now I would go out & check to see if there is a ground between the engine and the cab, unless you want me to.

Finally got a pair of jumper cables, and it appeared to straighten it out, (after pulling most all the steering column apart). I now need to find something to ground the engine to the cab. What should I use for that? Where would be the best place to hook the ground to the cab. Underneath, firewall, or it doesnt matter. . ?

 

[Philip]

Go down to a parts store and get one of the copper ground straps and run it from the engine to the fire wall. You can get them in different lengths. Just find a goodplace to bolt on both ends and get the eyelets to your bolt sizes.

 

[GIT-R-DONE]

Go down to a parts store and get one of the copper ground straps and run it from the engine to the fire wall. You can get them in different lengths. Just find a goodplace to bolt on both ends and get the eyelets to your bolt sizes.

Thats what I did, only I used the negative ground post on the battery and bolted it to the cab.



Everything except the radio seem to work (tried 2 of them and none work) and I plan on getting a CD player to put in and do my own wiring for it anyway.



Thanks for the help guys. Greatly appreciated !