Lights, why do I not have all my lights?

[mikekirby]

While I am waiting for my DME to return after being rebuilt I decided it was time to delve into my light situation on the 944. All but 2 exterior lights work. The two that do not are the Drivers Front Low Beam and the Passenger Rear Tail Light. All the other lights do work.

Starting the diagnostics on the front we swapped out with a known good headlight and that light did not work either, so it was not the light itself. To be sure we did a direct connect to the battery with both headlights and they did both light up on the low beam. We have a tool that send power through the wires and we have power going to the light from the connector and before the connector. All the fuses are good, nothing blown there.

Is there a circuit that needs the left front and right rear to be working to close the loop so that they all work? Is it a possible ground at the headlight?

[944 Ecology]

Two separate problems.

Fix the headlight first. It's not a ground problem.

[theer]

Make sure to check the orientation of the wires on the plug to the back of the headlight is correct. I’ve seen more than one where the wires have been mixed up, causing strange results. On the rears, could be corrosion on the socket preventing the bulb from getting good ground. Test light or volt meter is helpful to track down these issues.

[djnolan]

What year car? Hopefully an easy loose or dirty socket fix. But if not did you also check the fuses? Some of the lights are on separate fuses. Headlight switch could also be toast.

[mikekirby]

Djnolan;

The car is an 83. All the fuses appear good, and the switch does turn the lights on. We did use a power adapter on two different lights and was able to turn them both on, on the low beam. I think it is somewhere in the wiring, which is not a place I like to be. It always scares me because there is just so much of it and I have a hard time reading schematics. I should be able to do some more testing this week.

Thanks for the comments and replies. It does help.

[djnolan]

Right Tail light and side marker should be on fuse 13.
does the side marker light also not work?

Left headlight should be off fuse 1 and 3 / low vs high beam,
Are both low and high beam out?

Also you could drop the headlight switch down and make sure the connector is tight and nothing looks or smells burnt.

[mikekirby]

just the low beam is not working on the front. As for the side marker lights. Hmmmm, I can't say that I looked at those. I will look and see what shows up. It is sunny today where I am so it may be hard to tell.

I will also double check the fuses just to be sure.

[mikekirby]

Quick update. I have had the same lighting issue on my 1976 924 as on my 1983 944. I had an extra few minutes yesterday and decided it was time to take a closer look at the headlights, because I may be driving at night and lights are important. I started with the ground wires on the drivers side, managed to break the nut right off the bolt as it hadn't been apart in close to 40 years I would imagine. This meant I had to drill a new hole to mount the ground wires. After doing this and cleaning the area, I bolted everything back together and I now have low beam headlights on the 924. Next time out at the 944, that is the first thing I am going to be looking at. Thanks everyone for your help, and responses. I will give you all an update when I finally get there.