(1981 USA Automatic)

I Went to replace a (presumably) broken door switch and tested the wire for the hel of it with a testing light. I didn't get any juice, and the new switch predictably does not work.

Does anyone know how this system works? I'm guessing the chassis serves as a ground, and when the door opens the switch's movement closes the circuit. Where does that brown wire get its power from? And where do all of the lights that are triggered by that switch link up so as to be triggered by these switches?

Thanks, so many of you have been such a big help one month into this project. Should be driving it in a couple days after nearly 7 weeks of being on jack stands in my garage.

Thanks!

 

I didn't look at the wiring diagram but brown wires on these cars are typically ground wires. I think you need to find the hot wire.

 

All interior lights on the '81 get their power thru Fuse #23 (8 Amp).

Each interior lamp unit has a three-position switch either as part of the housing (swivel the lens) or as a small **** on the lens:
OFF - the lamp will not light regardless of door/hatch position.
ON - the lamp will be on regardless of door/hatch position.
AUTO - the lamp will light when any door or the hatch is open.

Each light should have three wires attached:
Red - should have 12 vdc at all times.
Brown - should be grounded at all times.
Brown/White - should be grounded when either door or the hatch is open. All of the brown/white wires on the switches are linked. (There are other non-linked brown/white wires on the car - all brown/white wires are switched ground wires.)

It is a great advantage to have the manuals and wiring diagrams - the best source at the moment is the set of 928 tech info CDs that Jim Morehouse has prepared. A search on this Forum will give you full info on that.

 

Wally, thank you. I have the manuals on PDF, but I hadn't had any success in finding anything, they are so densem it's easy to miss. So now I know that the brown shouldn't have lit anything up, and that my switch is good, I need to check the brown/white wires, since the lights all work in the ON position, but not the AUTO position.

To check if a ground wire is working, can I connect a test light's alligator clip to a hot wire, and use the tip to test an exposed part of a ground wire to see if it grounding properly?

Wally, I want to compliment you on your excellent service, I ordered a bunch of stuff last week, and your cust service people were beyond helpful.