Question about 83 SC Coupe dome light operation

[cky3396]

From what I understand, both interior 3-position dome lights should operate as follows:

Middle Position - Lights on when doors open (Check, this works on driver and drinker side)
Rearward Pisition - Always Off
Forward Position - Lights on with doors closed (Works on Passenger, but not Driver Side)

I popped both dome lights to get a better look at the wiring, and also pulled the driver side dome housing out to bench test.. the only noticeable difference between the two is wiring (two + and two - wires on passenger, one wire on driver).

Driver:


Passenger:


bench testing, the driver dome only lights up in center position. I must be missing something. What's the trick to get the Driver dome light to turn on with doors closed in Forward position?

[AG81]

Following...

[brianlay]

12 volt power is supplied continuously
Lights are turned on by either a ground from the door switch or a ground to the light housing when it’s installed.
The metal clip needs to be touching the car body

[brighton911]

What brian said !

[cky3396]

Originally Posted by brianlay

12 volt power is supplied continuously
Lights are turned on by either a ground from the door switch or a ground to the light housing when it’s installed.
The metal clip needs to be touching the car body

copy, looks like I got it.. headliner material was intterupitng contact between this part of the clip and the sheet metal it should be resting directly against.



after a bit of fine tuning I was able to make sure headliner was not in the way.. forward position works now


thanks all

[EC900]

There’s a few things contributing to the problem. I went through this a while back,
Yes on the ground at the fixture in the roof panel. My headliner was replaced long ago so there was an issue, one side didn’t work at all.
Clean the roof area and make sure no glue or headliner fabric is blocking the tabs from ground to bare metal.
Also clean and lube the door switches both contact and plastic plunger as I found mine sticking enough to not fully extend. Lots of tarnish and dirt.
Then check that the contact bands in all pivot positions of the lens is making contact, or if it’s bent and dirty. Seat the bulb correctly clean all contact points.

[cky3396]

Sound advice EC900 - I am going through my new to me 83 and lots of little things need some TLC. all contacts looking good and functional, its the roof ground that got me.

as an aside.. curious, what kind of glove box light do ya'll have? switched or rocker style?

here is mine... the plunger/spring loaded ball housing makes it difficult to use the switch - despite lubing it up and getting good action from the spring. the replacement part I find has no black toggle switch.

[EC900]

Same on 77. Toggle is 3 positions.
Forward is to light up with the plunger switch.
Middle position is Off.
Back position is Constant On. Doesn’t turn off when box door is closed !
Looks like your bulb filament is broken.
You’ll have to remove glove box liner to get at the plunger on the right side if bulb isn’t broken to check operation. Like dome lights plunger is the ground

[EC900]

[cky3396]

thanks EC, interesting you also have the 3-position toggle switched map/glove light but its impossible to find this same style for sale online.

the light & contacts, glove box button switch (when glove door closes), and wiring is all good. everything functions except for the action of black thumb switch



my issue is.. the white plastic (see arrow) that houses the metal ball/spring is flexing in the dome light housing. the ball and spring action is fine (lubed up nicely, no rust). if that white housing remained seated properly it'd be a whole lot easier to toggle between Glove Box Open/Off/On modes.

at any rate, appreciate the feedback here in thread. on to the next series of projects

[EC900]

Probably phased out over the years…# 911.632.103.00. they always used up old stock before issuing a new version, but the PET doesn’t even show the external switch version.
Seems new style is similar to the interior light is now the current version for the glove box light with part #911.632.102 using the lens 3-position internal switch action.
The interior light # 911.632.101.00 is a bit rounded and probably wouldn’t fit the glove open opening and snap-in tabs are different.
If your original switch can’t be JB Weld repaired, try contacting Unobtainium Inc.in NY.

[cky3396]

EC900, I appreciate you sir. thank you for the insights. I think I will be OK replacing with a rocker style to keep all the convenience lights matching, operationally speaking.

cheers