interior light quit working

[71bmr02]

the interior light in my slick top 71 was working perfectly and now its not.  i've checked double checked, grounded regrounded and nothing works

1 bulb and fuse  good

2 light will come on in the manual on position 

3 light will not come on when door is opened

4 ground is good

5 hot wire is carrying current see 2 above

6 nothing on brown black wire that is supposed to be what controls light on off from door jamb switch

7 door jamb switch cleaned and continuity tested good

8 carried a jumper wire from wires at door jamb switch to terminal on light body and jumper wire from jamb switch to ground, nothing

9 cleaned and tested all contacts in interior light switch body all tested good in all positions 

10 contiuity from end to end of interior switch body

 

it is a simple system and i'm  sure the solution is simple but i cant seem to find it. any help appreciated.  

[stephers]

Make sure that the screw for the switch in the door jam is tight, the switch grounds thru that   If it is loose, no ground no light

 

Thanks, Rick

[visionaut]

Well, it works at least.

 

Check wiring at BOTH door switches, not just the one in the door that’s not working… dome light goes to left switch, right switch goes thru left switch.

[71bmr02]

yeh, it does work so at least i can turn it on off manually.  door jamb switch was grounded to another ground and nothing there so i feel certain it's not the ground.  still testing 

[visionaut]

There’s no ground wires. The switches provide ground when the doors open.  (Button out = grounded)
 

Here’s a reference drawing I pilfered from our resident 02 electrics Michelangelo, John76… 

 

You aren’t trying to run the later model switches, ignition/seat sensors or dash pod in your 71, right? (different wiring)

 

Tom-too

[71bmr02]

quick update, got it working on both sides of switch.  because i'm so f#$#^% intelligent i knew I couldnt possibly have overthought it when i reinstalled the switch and did something as dumass as mis-wiring, well you can see where this is going.  thanks for all the replies.

Gale H

[Overdraft]

I had the same situation- went through similar troubleshooting and in the end swapped out the dome light with a new one and it worked immediately.  I am suspect that the X contact within the switch itself was not contacting or grounding to the car correctly..despite pressing/ cleaning the old dome light.

Edited April 1, 2023 by Overdraft

[71bmr02]

at least all the contacts in the light switch are clean and i know the door jamb switch is in good working order

[its55]

39 minutes ago, 71bmr02 said:

at least all the contacts in the light switch are clean and i know the door jamb switch is in good working order

 

Can you test the switch itself for continuity?

 

[71bmr02]

yeah, best to have it out i was concerned the slide contacts may have been corroded so i checked across the contacts just to see if they were in working condition.