No headlights!! (85 300D)
 

Jumped in the car last night (85 300Dt CA), flipped the headlight switch, all interior illumination came on, but no headlights! Both were working on the way to the restaurant. If I flip the stalk to high beams, the high beams work fine. Any suggestions? I did a search; couldnt find anything. This buggy sat for the winter and now it's one spring problem after the other :mad:

Thanks.

You know, I've seen this situation on the SD every so often with the age of the combination switch. The switch must be all the way rearward (toward the driver) to activate the low beams. The switch must be all the way forward to activate the high beams.

Now, there should be proper detents in both these positions so that you get either low beam or high beam. But, as the switch gets old, the detents go away. So, gently pull the arm rearward (toward you) while the lights are on and see if you can get the low beams to work. If you can, it's time to replace the combination switch.

I recently did this on the SDL because the contact for the washers was non-functional. It's not too bad a job. The switch is a bit pricey.

The headlights are wired and fused separately (left vs right). But the combination switch (dimmer) is common to both. Do your fog lamps work? (They should not come on when the headlights are selected to "bright.")

Yep, I'd forgotten about that. This now seems to lead directly to the combination switch.

Well, it wouldn't be the first "switch" to start sticking this spring (remember my kickdown switch Brian?? :D

Cool; I'll run the check you describe. Where is the combination switch? In the cluster or under the hood?

It is the lever on the steering column that you use to select normal or bright headlights. Also the wiper/turn signal switch, hence the name "combination switch."

My car's headlights are slow to come on when it is cold. if it is -10 below, it takes about 10 seconds for the headlights to come on.. in the spring time and the summer, they work as normal... I am thinking that it is the main headlight switch, but now that you speak of the combination switch... it no longer holds in the left or right turn signal position, so It will be rewarding to replace that and see if it helps the headlight when it is bloody cold out..
Jason

Boy do I ever................what a nightmare................. :D

The switch does not "stick". More likely is is sloppy and falls out of the detent position. There is a space between the two detents that is "no man's land".
You don't get either the high beams or the low beams. :eek:

Tango,

That's interesting. The yellow fog lights do come on when the highs (or so I thought) are on, so what does that mean? I also noticed a couple other things upon second look: (1) I have to have the blinker arm pushed forward to get lights (high position right?); (2) the lights dont seem all that "high" when on (maybe fog light operation suggests not high); (3) there's some water in the bottom of my headlamp lenses, sloshing around.

I dont get it.

Is there any way to test the operation of the combi switch with a multimeter?

I think that I might have it.

Any chance that the water sloshed up and hit the filament while the filament was operating? If so, it's now history.

The high beams may have survived if they were not on during the sloshing event.

Pull the plugs to the headlamps and do a test with a voltmeter and see if you have 12V on both low and high beams. You might be surprised. :eek:

Per the wiring diagram, the fog lamps receive power through the same circuit as the right low beam headlight. So it should not be possible for the fog lamps to be on at the same time as the high beam headlights. Also the fact that the fog lamps work seems to suggest that the problem is not with the combination switch.
The only thing that makes sense to me is that your low beam elements in the head lamps are burned out. You could check for voltage at the headlight connector. Left headlight is yellow/black wire; right is a yellow wire; ground wire is brown on both sides. If you have power there, the lamps are the problem.
In any case, water in the lamps means it is time for new ones.

Will do. The right one has about 25% water in the lens. Ridiculous. It could have definitely sloshed around. I couldnt get any results by playing with the combination switch arm (directional arm). Everything seemed tight. I will do the Volt test.

No volt test yet, but anyone have a suggestion for which sealed beam headlight to get? You've got the silverstar, the halogen, and the extra vision halogen. I guess all of them would fit my 85 300D? They're all 7".

Well, any sealed beam is not going to do a very good job.

Consider these:

http://www.rallylights.com/hella/7in.asp

They will last the life of the vehicle and the light output is fantastic. When the halogen lamp burns out, you simply replace it with a standard H4 lamp.

I made this change to the SD and was exceptionally pleased with it.