New 1985 928 project - lighting help?

[zmoretz]

Hi folks, new member here, just acquired this project but grew up with my dad's 1979 Euro-spec and have had a 944 and a 911 in the past, so may be somewhat aware of what I'm getting myself into. Or not. Car was in a field for 3 years but is mechanically sound. Electrics and body need work. First issue is that most but not all of the lights seem to be out. Yes, it could be bulbs, but I'm thinking more likely a relay? or relays? given that the signals and flashers work, and a couple of parking lights come on, but no brake lights, headlights or driving/fog lights. Headlights do pop up nicely, and appear to be new halogen lenses, so presuming the bulbs inside are probably OK. Not sure about backup lights... (PO had done a lot of work on it before he parked it - fluids are pristine, new rack, new radiator, new timing belt, new water pump...) Also, while I am at it, any reason not to replace as many bulbs as possible with LEDs, and if so any guidance anywhere on which LED sizes replace which bulbs? Thanks in advance for anyone "shedding some light"!

[GUMBALL]

Couple of information sites:

Theo's 928 S4 - GT - GTS website

Porsche 928 Maintenance Tips and Procedures

Very helpful

[zmoretz]

Thank you @gumball!

[Danglerb]

I would start with cleaning all of the fuse contacts, wiggle all the relays while spraying with contact cleaner, and do the normal ground service.

Maybe buy the latest best version of a loadpro or power probe. You are going to need the tricks they can do, measure voltage at any point with a slight load so enough current flows to show weak (high resistance) connections in the circuit, apply either ground or power to the probe tip.

[harborman]

Originally Posted by Danglerb

I would start with cleaning all of the fuse contacts, wiggle all the relays while spraying with contact cleaner, and do the normal ground service.

Maybe buy the latest best version of a loadpro or power probe. You are going to need the tricks they can do, measure voltage at any point with a slight load so enough current flows to show weak (high resistance) connections in the circuit, apply either ground or power to the probe tip.

Absolutely! You need to pull all the fuses and relays and spray contacts with Deoxit or CRC contact cleaner. Remove and clean all grounds. Check battery ground strap to frame. Check and clean ground to motor. I had to replace my ground strap on the battery (internal resistance).

[zmoretz]

Thank you! I have wiggled/checked all the fuses, but have not done the relay service you suggest. I will try that. Also, as a follow up, I replaced the headlight relay and now they work, but still no other lights working EXCEPT the turn signals. That seems odd….

[stepson]

Originally Posted by zmoretz

Thank you! I have wiggled/checked all the fuses, but have not done the relay service you suggest. I will try that. Also, as a follow up, I replaced the headlight relay and now they work, but still no other lights working EXCEPT the turn signals. That seems odd….

No warning lights work? At All?