My 95 850T started with door open chiming and foot well light staying on, so I opened the door up Saturday to see what's up with the microswitchs. There are three wires to it: yellow w/ red, white w/ black, and solid black (ground). I hooked up a VOM to the wires and tested both open and closed latch. With latch open there is connectivity between all 3 wires. With latch closed, infinite resistance between each of the three.

1) Is this normal functioning of the two microswitches ?
2) I would have anticipated that the black ground wire to have connectivity with the other 2 power leads, but why are those 2 other wires showing connectivity ?

TIA, Al
--
Optimist - half full, Pessimist - half empty, Engineer - The capacity is twice what it needs to be.

Here's the 850 wiring manual. See Central locking Page 160 for the sedan

http://www.matthewsvolvosite.com/downloads/1995_850_wiring_diagram.pdf

Thanks Bill,
The wiring diagram confirmed the micro switch is working as designed. After taking the door apart to access the locking unit, testing the switches, it turns out all that was needed was the sticky latch mechanism to be cleaned and lubricated.
--
Optimist - half full, Pessimist - half empty, Engineer - The capacity is twice what it needs to be.

Thanks much. I'll go over this tonight.

Edit - For the door lock micro-switches, look at the "Interior lighting" section, page 94, module 3/74.
--
Optimist - half full, Pessimist - half empty, Engineer - The capacity is twice what it needs to be.