'78 SC Dead Short Fuse 4 Parking Lights; Please Help me Track this Down

[KerryM]

I had not driven my car at night this summer and checked all of the lights before I left last night. The drivers side parking lights were out.

I was not surprised to see fuse #4 blown, but a bit surprised when a replacement immediately blew giving me a minor shock. After searching the forums, I unhooked the engine compartment light that never worked anyway and taped up the wires. I traced the wires back as far as I could and found no evidence of shorts. So unfortunately no love there.

I replaced my tail light assembly with LEDs several years ago and they work like a champ; except for the parking lights. The brake lights do work fine (same LEDs). All other tail light functions also work fine.

I opened up the front parking light and cleaned the connections. No love there either.

What should be my next step? Open up the headlight bucket and check connections there? Trace the engine compartment light wire to its connection point and remove?

Thanks for reading!

[KerryM]

I took the right parking light apart and cleaned it up as well as I could; connections were a bit corroded/rusty.

Good news is I'm not blowing fuses anymore. Bad news is the front parking light still does not work, but the rears are great again. So some progress.

If I used my multi-meter correctly, I'm not getting power to the bulb socket when the bulb should be lit.

Next steps?

[PeteKz]

If messing with the light sockets fixed some of the problems, then I would suspect you still have corroded connections in the housing or between the housing and chassis harness. If you were blowing fuses, and now you are not, you may have a short in the wiring inside the light housings. Did you disassemble those yet?

The trunk light is on the same circuit as the left turn signals, so check for possible shorts there.

And read Frank's travails and solution on a very similar problem in this thread:
https://forums.pelicanparts.com/porsche-911-technical-forum/1167278-turn-signals-inoperable-but-hazards-l-r-independent-parking-lights-work.html

[KerryM]

Thank you PeteKz for your thoughts! Here is what I did this evening.

I removed the covers from the left front turn signals and parking light.

Turned on my headlights. Right parking light was lit; left not. I tested with a multimeter and was getting no power to the bulb with either the standard ground socket or my negative battery post.

Turned off headlights. I have no continuity between the black/white wire in the turn signal assembly and the black/white wire in the parking light. I also have no continuity between the ground wires in the two.

And then the obvious hit me. I noticed two empty prongs in the back of the turn signal assembly, and two very, very short white wires taped on the ends. I got continuity with the empty prongs to the bulb socket in the parking light (power and ground). So this tells me that the parking light never worked and the short was in the engine compartment light.

Too late tonight, but tomorrow I'll tie in bit longer white wires with connectors and plug them in.

Thank you for directing me to the turn signals!