I ]think what the
OP 85911 was holding could be one of the hvac slider control instrument sockets that have a push-in 1.2w bulbs (900.631.132.90) and the that socket easily pops out because of old, stretched, vibration, etc. I have similar empty bulb holder.
OP looks to have an empty opening, but I doubt it because the grommet is still there.
Yes - a little tape wrapped around will secure it. There are two bulb sockets that light up the slider… one for the Fan/Def Off/Down arrow and the other the fan symbol/Up arrow. The socket is part of the loom but is replaceable. Here:
What
Missed Approach posted is the ashtray socket bulb, as a unit pops out but not sure if bulb is separate or replaceable with a 1.2w bulb. I have this unit (photo) and it lights up but hard to see the wiring. I know some wiring with black/blue stripe is the dash loom. Brown or brn/wht wire also part of interior light circuit. The ashtray bulb is not visible from underneath- I looked and can’t see it and photo didn’t show any.
So if
x98boardwell has no ashtray lamp, that’s the part (or bulb) needed.
But to expand on the original poster - Here’s photos of mine, I too have
an extra mystery socket. My ashtray lights up and I know the bulb that’s hanging belongs in the slide controller right side. The empty mystery bulb socket (to the right of lit bulb) doesn’t appear to have ever been used has no bulb, maybe part of some optional instrument (?). Its wires are covered so the circuit is unknown for now.
My Fog/R.Defroster knobs and Brake/Seatbelt lamps are operational which bulbs are internal anyway.
I’ll be doing some radio work this weekend so access will be easier to get a better look at my ashtray light to see if that bulb is replaceable and maybe put a bulb in the empty mystery socket to see if it works… and at the least add more light to the dash or maybe the floor.
