instrument lights

[crpntr78]

Hello. I have an '86 k10. I recently replaced the cab with one from an 85 c10. I've had it for a year getting it ready but don't know how long cab sat before I got it. Having an issue with my instrument lights not coming on at all. I've checked all wires and fuses, cleaned grounds and PC seems to be alright. No noticable tears or anything. Replaced HL switch,no help. Also dome and crtsy light stay on all the time. Again wires seem fine, no grounding anywhere that I've found. New door switches also. And another thing, choke light comes on AFTER starting and stays on while engine running. Oil pressure gauge reads 40lbs. at idle. New sending unit and switch. Tried taking off wiring plug and reseat but to no avail. Anything I'm missing? Thanks for any help.

 

[1987 GMC Jimmy]

First, let me preface by saying that this is in no way a smart ass answer, but I see you didn't mention anything about the bulbs. Do you have new bulbs, or do you know for certain that the ones in there work? The dome and courtesy light issue probably has to do with an open circuit in the door jamb. The switch is supposed to break that continuity and turn your lights off. Is it the OEM style switch or is it aftermarket? Have you tried playing with it to see if maybe it's not going back down all the way? Also, do you have aftermarket courtesy lights because those trucks only had just one little dome light to my knowledge, and that was all the door jamb switch was responsible for. Also, have you verified the functionality of your choke? If you still have the Quadrajet, I think the choke light was more like a monitor of sorts because those were divorced or hot air chokes. If you have a later aftermarket carb, you can either manually or electrically choke it, and that wire would cease to be beneficial. I did a Holley carburetor on an '89 P30 once, and I used one of the little pre-ECM, useless sensor wires that got 12V when the key was switched on, and that would operate the choke. It, too, had a Quadrajet stock. That's my opinion on the carb. I don't know a whole lot about them except how to install them and how to make the choke work (more of a TBI person).

 

[Georgeb]

Regarding your choke light check here.

Regarding the dome light and courtesy lamp under the dash the jamb switch acts to complete the circuit to ground through the white lead with the orange lead being hot at all times so look for a short to ground on the white lead.

 

[Georgeb]

What harness is in the cab the 85 or 86? Find a wiring diagram for checking out the instrument lamps. Verify if there is power getting up to the panel.

 

[crpntr78]

Thanks for the responses. Yes, the bulbs are new. The dome light is OEM. What I'm calling the crtsy light is the one under the dash on the passenger side. Other names for it? The door switches are OEM. The wiring harness is OEM from 1985. The choke light only came on after I hooked up the TCC lockout for the 700r4 tranny along with losing the alternator gauge. It's now flat lined all the way to the left. I have unhooked all wires to the TCC but no change. I've traced all wires and not and have not found a short anywhere. I'm running a Holley 650 4 barrel carb with electric choke. Thank you.

 

[crpntr78]

Good morning. Good news. I was able to get the dash lights working. I took the instrument bezel out and cleaned up the harness plug till bright and shiney and was also able to get the dome light working. Took new switches out and cleaned and WD-40'd them and working perfectly now. Still having issue with choke light coming on after engine startand the alternator guage not registering.

 

[Georgeb]

For the choke light is there power to the choke when the engine is running? If not check the oil pressure switch.

 

[crpntr78]

Good suggestion. Never thought to check that. This is such an informative site. Thanks everyone.

 

[crpntr78]

I checked for power at choke with engine running. There is power there.

 

[Georgeb]

Ok, how about this?
http://www.gmsquarebody.com/forum/showthread.php?t=14919&highlight=choke+light

 

[Georgeb]

Also this.
http://www.gmsquarebody.com/forum/showthread.php?t=4350
Read down this one a bit. Great info here!

 

[crpntr78]

Thanks for the reply. A lot of good info from those threads. Checked them out, did the steps and replaced blown guage fuse. Choke light went out and temp and ammeter guage worked for a time. Restarted and put into gear and choke light came on and guages went flat again. I'm assuming ( I know) the fuse is blown again. I would like to know why. Thanks.