dome and cargo light grounds

[dirtautoguy12]

I have a 1996 chevy k1500 cheyenne regular cab with no power windows or door locks or anything like that. however since I got this truck the dome light and the cargo light doesn't work I was wondering if someone could help me with this problem here are some details and what I know.

1. the 2 lights next to the dome light that you click on both work

2. all the bulbs are new

3.the two curtesy lights kind of up under the dash work

4. my truck used to be a company truck that had a cb radio wired into it and there is a orangeish colored wire that is under my dash that has been cut it has 12v to it when the key is on but not when it's off.

5. if I ground the middle dome light to a screw in it the light comes on

6. both the cargoi and dome light have 12v to them at all times

7. the 3rd brake lights work

8. I have taken the door seal off and checked the wires they looked good and i didnt see any shorts

9. the glove box light works

10. the number 3 20amp fuse is good too

11. all other lights work

If someone could help me with this that would be great I have been trying to figure it out for a long time.

[Schurkey]

Originally Posted by dirtautoguy12

5. if I ground the middle dome light to a screw in it the light comes on

6. both the cargoi and dome light have 12v to them at all times

Apparently the switch controls the ground on those circuits. Find the break/open on the ground side. Could be a defective fixture, broken/cut wire, defective switch, or the switch itself doesn't have a proper ground.

I'm thinking that the cargo light is set up to not come on when the vehicle is in gear.

[dirtautoguy12]

Ok so where would those places be to look?

[Schurkey]

Originally Posted by dirtautoguy12

Ok so where would those places be to look?

Originally Posted by Schurkey

Apparently the switch controls the ground on those circuits. Find the break/open on the ground side. Could be a defective fixture, broken/cut wire, defective switch, or the switch itself doesn't have a proper ground.

I'm thinking that the cargo light is set up to not come on when the vehicle is in gear.

Start with the fixture that the dome light is in. Trace the ground wire to the switch, verify that the wire has continuity. Test the switch. Test the ground wire from switch to the steel of the body/chassis.

"I" would consider disconnecting the wire at the switch, pulling the bulb out of the dome light, and then using an ohmmeter to verify continuity between the switch-end of the wire to the ground-side spring clip for the bulb. If that's good...it's either a defective bulb or a problem with the switch or the ground side of the switch.

Try the cargo light with the shift lever in "Park". If it works...it's good. If not, troubleshoot it just like the dome light.






Now you know why electrical diagnosis is done at hourly rate--a defect can occur anywhere in the circuit, and no matter where it happens...the circuit doesn't work. You won't know where the problem is until you find it. In general, FIXING the defect is mega-easy. The trouble is FINDING the defect.

[dirtautoguy12]

Ok thanks so there is a orang and a white wire to the dome light I think decided the whit was hot, orange ground. What do switches look like are they like relays? And last but not least would the switch be where the cargo light wires and dome light wires come together and are tape?

Thank you for the help

[dirtautoguy12]

Wow I feel really dumb I know what you mean now I'll check it out this week and let you know

[dirtautoguy12]

Ok so this is what I found:

1.i traced the wires back down alone the floor boards the 2 orange wires have power to them

2. The blue wire with a white stripe that connects to the cargo light switch has power with the switch on or off is that right?

3.there are 3 white wires one white wire has power with the brake pushed the other two don't have power

4. There is a lighter blue and lighter yellow wires that have power to them however they don't have very much power but I don't think they have anything to do with the lights

[dirtautoguy12]

I fixed the problem it was a short in one of the wires they all looked fine until I noticed a very slight bulge in one of the wires, and on one side it had power, but on the other side of the bulge it did not. So I just spliced a good piece of wire into it and WALA!!! I have cargo and a dome light thanks for the help

[Schurkey]

Originally Posted by dirtautoguy12

it was a short in one of the wires

That's not a "short", that's an "open". At any rate, good job. You've gone where most fear to tread.

[dirtautoguy12]

Thank.