108 electrical troubleshooting

[deafen]

My 108 has some electrical weirdness.

The left-side lights all work correctly.

On the right front, the turn signal light works, but the same lamp does not light for the parking lights or headlight position.

On the right rear, none of the lamps light up, but all the filaments look solid (i.e. the bulbs are not burned out). I don't know if the brake light works (haven't been able to test it with anyone else), but the turn signal and tail/parking light do not light up.

The license plate lights do not light up at all.

The fuses all look good. Any suggestions on other things I can check?

[300SDog]

Sounds like oxidation/corrosion of electrical connections if filaments check out okay. I'd be plugging and unplugging connections, lightly sand papering with #220 grit or steel wool to revive em. Also using an aerosol can of electric parts cleaner.

Keep in mind that 90% of electrical problems are ground related - so scrub the sockets around the collar where bulbs ground.

And on the right rear corner, try attaching a grounding wire from the tailight unit securing nut to sheetmetal inside the trunk - or check the existing grounding wire if one is there.

[Tomguy]

Remember, the bulb for the front signals is a dual filament bulb. And it only goes in one way properly (it will fit the other way, but it isn't right and it won't work right usually).

The license plate lights require a large-bladed slotted screwdriver to remove and inspect. The bulbs are the "tube" type (they look like mini-flourescent lights). I actually cracked one of mine once overtightening it when I was replacing it. Check and see if there's corrosion inside, and if the filaments are good or not.

There is a plug on the light itself where the wires all go into the unit. Make sure that plug is in tightly and the contacts (male AND female ends) are clean. The side markers get their power off this plug as well, so if that's corroded, that's why that light isn't lighting up too.

[250 Coupe]

The left and right parking lights are on separate circuits due to the standing or parking position of the headlight switch.
I'd start looking at the headlight switch. Also, there may be separate fuses for each side. Try spinning the fuses in the holders as corrosion can set in and break the circuit even though the fuse itself looks good.
I back into parking slots at mini-malls and check the reflection in the windows every few months to check all of the rear lights.

Michael

[deafen]

Finally dug into this. Turns out that fuse #7 controls the right-side tail lamp, parking lamp, *both* license plate lamps, and the dashboard lighting.

Yup, the fuse was blown.

So between that and adjusting my NSS, I've got almost all my lighting issues sorted out! The one thing left to do is fix the dashboard dimmer. Unfortunately, I'm not one of the lucky ones who has a car whose previous owner already removed the knurled nut, and I've got gigantic hands...

[Tomguy]

Originally Posted by deafen

Finally dug into this. Turns out that fuse #7 controls the right-side tail lamp, parking lamp, *both* license plate lamps, and the dashboard lighting.

If you don't have a fusebox listing, you can check out my scan of the fuses. It's a scan of my own, which is a bit aged, but it can come in handy for some of you without any fuse map at all!

[deafen]

I saw that -- very cool. My fusebox still has the paper insert; I thought it was pretty funny that the same day I found it in my car, you posted it online.

And thanks for the Kangol scan -- I didn't realize that you could hang the seat belt latch into the door part. I'd just been laying mine across the seats! What a dope.

[j9fd3s]

Originally Posted by deafen

Finally dug into this. Turns out that fuse #7 controls the right-side tail lamp, parking lamp, *both* license plate lamps, and the dashboard lighting.

Yup, the fuse was blown.

So between that and adjusting my NSS, I've got almost all my lighting issues sorted out! The one thing left to do is fix the dashboard dimmer. Unfortunately, I'm not one of the lucky ones who has a car whose previous owner already removed the knurled nut, and I've got gigantic hands...

try turning the dimmer knob back anf forth, that fixed mine.