so im working on restoring my truck. the cab that im using now was off of a 87' gas truck. i swapped all the wiring in the dash out of my diesel cab to my new one. now the other night i got the truck up and running but before i could get it to turn over i had to change out the starter relay and before i changed it out all my lights in the cab worked including the back lighting for the guages. after i put in the new relay the motor started which is great but then the back lights on the guages stopped working but the actual gauges work . and today i started it up and now the dome light wont come on, the light in the ash tray and still now lights on the guages or power going to the headlight bulbs and such. the only light that works is the one about where it says wait to start and such.
now ive looked as some wiring diagrams and i cant find if theres a ground or something somewhere that i didnt hook up or something. all the fuses are good so im stumped. everything is plugged in right too. im not sure how to start to figure this out.
i was thinkin maybe its the switch to turn the dome light on and the extior lights might be bad but then how could that make the ash tray light not work? any help would be greatly appreciated . thanks.

 

Ground from the headlight switch to chasis ground needs hooked up. IIRC, there's a ground that goes to your e-brake switch. Put a ring terminal on it and run it under the screw that holds your hoods pull cable in place. Fixed my problem, I went from a 84 to 86 cab with the 84 engine wiring harness and cab harness. My dome lights didn't work afterwards, there may be a separate ground to the switch itself but I can't remember. I only remember having to add a ground somewhere


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Oh, even better... At-least your windshield wipers didn't come on when you opened the door like mine hahaha. Dome light didn't work, but wipers did... Only with the door open, never by the switch.


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If you send me your email address I have a great PDF of wiring diagrams for 1st gens that I can send you.

Dave

 

thanks. ill give it a try today. i hope it does the trick. that sucks ur wipers turned on with the door, did you get it figured out? ya my dome light was working with the door and such until i stated the truck up for the second time yesterday.

 

Yeah, the ground fixed it. When the door switch would get grounded from the door being open it'd supply the required grounds needed for everything to work.


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so i figured out what the problem was for the extior lights and back lighting for the guages. all my grounds checked out good and it ended up being the the plug that goes onto the headlight/running lights switch. it musta shorted out cuz the plastic was all melted in the middle and the wire connections are toasted. luckily i was able to use the one off of the gasser harness and it works like it should now. the ash tray light works as well.
bad news is the dome light still doesnt work. i didnt have time to look into it yet but im thinking it might be the connection for it from the main harness or whatever it is grounded too but i doubt its a ground. if i cant find the issue ill just wire it up with the map light above the info pannel cuz that still comes on when i open the doors and such.

thanks new dog 93 for the wiring diagrams!!!