2nd Gen Non-Engine/Transmission tail light/dash light problem with twist... need some advice.

[TGriffith]

I continue to have electrical issues with my dash and tail lights, I've replace the switch and the harness looks fine (no melts or burns). I've read through all the posts I could find here but haven't been able to resolve this issue.



Here's the twist to this, sometimes the dash and tail lights will begin to work again which may last for a couple of days then it's gone. which sounds like a short to me (or maybe a ground problem), the other thing I've noticed is that when I have the lights on and niether the dash or tail lights are working I hear a clicking sound (like a relay) under the dash, there's a black box there that I think it's coming from, I believe it's the CTM which does tie into the interior lights from what I can remember but didn't think it had anything to do with the dash/tail lights.



Any thoughts on what to do next, I have a trip coming up and can't run without lights.



thanks for the help



Terry

 

[Billy Diesel]

Maybe it is a bad fuse under the hood? That's the only other spot I can think to check.



Good Luck.

 

[DieselDoghouse]

I'm gonna suggest the unconventional - start from the outside and work in. Disconnect all parking lamps, then turn the switch on and listen for the click. You might have a bad ground on a lamp that is hatching gremlins—see my post where a bad ground on front lamp cause wipers to activate any time left turn lamp lit!! Good luck!

 

[radixr]

Electrical Problems

Terry,



This is a long shot but if you have recently replaced your batteries with a battery that is not quite as tall as the stock ones (Optima, for example) it is possible a hold down screw has penetrated an electrical wire bundle. This happened to me a while back. The screw had damaged a wire bundle under the driver's side battery and drove me crazy until I discovered it. :{ :{

 

[JPittinger]

Those cheap pinch-on wire connectors someone used on my trailer plug wiring caused a short in my taillight circuit that caused taillights and dash lights to go out. Sometimes it would blow the fuse, sometimes not. Got any of those cheapass things out back? If I didn't hate politicians so much I'd say they should be outlawed...

 

[TGriffith]

Thanks for the replies!

The batteries were replaced around the same time this started, don't know if they are differnet in size but I'll pull the tray and have a look. I checked for those crimp on wire things and didn't see any but I will check again and I'll double check the fuses. I'll also try disconnecting the parking lamps.



thanks for the help, I knew the TDR members would have some more ideas on what to check!



Terry

 

[TGriffith]

updated question

Well, I've gone through checking connectors, fuses, batterys etc. but still have the same issue. One thing I noticed when testing the connectors on the back of the the light switch with a multimeter is with the probe on the back of pin 1 and the other probe on the frame the dash lights and tail lights come on, and my actually work for a short time after I remove the probes.

I thought that maybe it just wasn't seating correctly. I tried wiggling the line,pushing it in and out and pushing the probe into it again without touching it to ground and it still didn't work, but as soon as I touch a ground point it works again.



So my question is where would the dashlights ground to? is one of the pins back of the light switch, if so where does it ground to? any other ideas on ground points to check?



thanks for the help

 

[DavidC]

You really need to spring for a Dodge service manual. Electrical problems on these trucks can get very involved very fast and with the manual you can go page by page to locate the problem with the wiring diagrams. As to the ground for the instrument lights, Drivers side, under the dash, left side of steering column you will see a very large electrical connector (white in color) with a bolt in the middle. With the wires coming from the dash side of this plug a wire comes out of this loom and goes to the body ground. I hope this is your problem area.



Dave

 

[cojhl2]

So what is the clicking sound? Could it be a circuit breaker? Some people (like me) replace the tailight fuse with a self resetting circuit breaker. I don't know if it would be loud enough to hear it break though. .

 

[TGriffith]

So what is the clicking sound? Could it be a circuit breaker? Some people (like me) replace the tailight fuse with a self resetting circuit breaker. I don't know if it would be loud enough to hear it break though. .

The clicking is coming from a black box under the dash (next to the ash tray), I believe it the CTM still not sure it's related. I also have a new thing that started yesterday, the seatbelt light (the one that comes on when you don't buckle up) stays on all the time now.



I currious why you replaced the fuse with a breaker? Where you blowing fuses that often?

 

[cojhl2]

Tgriffith,



I have a first gen where the fuses are under a dash panel that must be removed and the fuse block twisted around to get at the fuses.



The only time I ever blew fuses in the past was when I had trailer wires hooked up direct and once in a while you would get a trailer that had faulty wiring. So,, I put a circuit breaker in place of the fuse.



Since then I have the trailer wiring hooked up thru a set of relays which are powered from a circuit breaker'd relay switched circuit direct from the battery. (In other words you must turn on the trailer to get any lights at ll to it) That separates the pickup lights from the trailers now. This also allows me to look like a cattle hauler coming down the highway without worry of overloading the orignal circuits and switch.



But,, I do like circuit breakers in general better than fuses anyway.