924Board.org

[Buffalorider]

Hello everyone...first post here. Just bought a 1977 924. Very nice condition. With some tinkering, I have it running very nicely. Now, I am moving on to the lighting issues. Hopefully some of you have been through this and can save me some time.

When I turn on just the running lights, the left side works and there is nothing on the right. Yes I replaced the bulbs. Blinkers work front and rear on the drivers side in a normal flashing cadence. When I flip the lever to the right side, ALL the lights flash front and rear (on right side) but at a higher pace to include the running lights that don't initially come on and stay on as if I were driving at dusk or dawn.

Here is what I did. I ran a jumper wire from the license plate lights to the right rear running light bulb because the license plate lights supplied some low amp power. This caused the running light to come on as well as the blinker light. Shortly thereafter, I blew both bulbs on my license plate lights.

I am constantly reading that grounds are the issues with these problems, but that does not make much sense since the lights on the drivers side work correctly. I do not think it is a relay since the 4-way flashers work. Any of you guru's have a clue where I should start?

Thanks so much for any help. This really is a nice clean original car.

12/12/14 update: I see folks are reading this but no replies. I ended up cleaning every ground connection I could find in the engine compartment and hatch back area. Even got under dash and took out fuse panel to check the grounds attached to underside of dash and no luck. I ended up splicing into the wire that supplies power to left rear tail light and connected the right rear tail light wire and now I have two lights back there. However, blinkers still flash normal on drivers side, but very fast on passenger side and ALL the bulbs work. The 4-way flashers flash at a normal pace as well. makes no sense but electrical never does.

[fiat22turbo]

Try your column switch, they are infamous for failing and causing odd problems with either the turn signals or the headlights/brights.

Sometimes pushing in on the switch or towards the center of the column can help, but that just indicates the plastic housing is cracked.

At the very least, cleaning the connections on the column switch can't hurt at this point.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[jason c]

Bad grounds, bad relays, loose fuse connections, bad switches, shorted wires and corroded connections can all cause this problem. Have you tested the power and grounds at the bulb sockets, switches & relays independently for proper power, grounding and resistance?

[Buffalorider]

fiat22turbo I will check that area. Good points.

Jason c, if any of the things you mentioned were actually bad ie: grounds, relays, fuses, switches etc, why would the drivers side work perfectly? I followed all of the wires from the rear of the car up to the fuse panel and they all go into the same area. Not really sure how to check for "correct" resistance or power. That may be above my pay grade and I have to live with a fast blinker on the right side of the car. One would think that after a short time of "fast blinking" it would blow a fuse. But is doesn't.

[jason c]

Some lights are on different circuits. Grounds are not only the group of wire bolted to the chassis, they include all ground connections (switches, relays, bulb holders....)The turn signal "stalk" is a switch, the flasher "relay" controls the blinker pulse and The bullet fuses are known for getting loose. An improper power supply along with a compromised ground can cause similar issues.

If you can afford $20 for a multimeter and can dress yourself, you can check for resistance. It's very easy. Set the meter for ohms, put the meter + on one end of a wire and the - on the other. The closer to 0 ohms the better. High resistance is like a roadblock for current. With a meter you can check for power, ground, resistance, shorts, continuity etc.

[pmcaya2]

Sounds like you're doing all the right things.

In addition to a meter, I recommend that you pick up a can of DeoxIT D5 at Radio Shack. It's invaluable for restoring electrical connections and switches. I think it's the best product of its kind - much better than WD40 and such. My can has paid for itself many times over. Perhaps spray into the steering column switches & contacts. We're dealing with a 35 year old car and switch contacts can be a problem.

I'd assume that the wiring is correct unless something indicates otherwise.
Good luck and keep posting. - Peter

[Buffalorider]

Thanks Jason. I will get a meter. Steering column switch seems solid. I do not believe it is cracked or broke. Am also wondering if bad head light on right side could cause anything as all problems are on that side. New light on the way.

I am starting to think it is the relay but would that be true if the drivers side and 4-ways flash correctly? Sure don't want to waste money on new relay. Thanks guys, I am going to narrow this down. I'll put up some photos of this car shortly.

[Buffalorider]

[Patroller]

Looks great! Could be the one I bought new in the summer of 1977. I kept it until about 1990 and sold it with less than 30K miles. Last 4 digits of my VIN were: XXXXXX1978. Any chance it's the same car. That color was very rare.
_________________
Red 1979 924
Red 1979 924
(Yes, I have a pair of twins)

[Buffalorider]

Probably not the same car. This was purchased new here in Colorado. I have original window decal.

Strange things are happening with the lights....check this out. The headlight was out on the passenger side so after putting in a new one, all the running lights worked on that side but now the right rear blinker was staying on with the running lights which it had previously not been doing. I then find a bulb that is not working in the hatchback area on the left side rear fender area sort of like a courtesy light which is installed actually in the carpeting. When I removed that burnt bulb, the right rear blinker lost illumination as well as the front right!! I think the whole issue with all the lights revolves around every one of them being in good condition and working which will then correct the entire system. I will keep you guys posted.

[!tom]

Sounds like bad grounds. Your system is grounding through light bulbs instead of the intended grounds.
_________________
78 924 NA
5-lug

[Buffalorider]

!tom I might agree but just not sure where else to check them. ALL rear lights are grounded at rear of car under the carpet near the license plate lights and those are very clean. Under dash above fuse panel is clean as well. I cleaned up both headlight grounds to the frame, the negative battery ground as well as the ground near the coil. Are there others I am missing somewhere? Thanks

[!tom]

Have you tested with a test light? Have you verified a good connection between the bulb bases and the bulb sockets?
_________________
78 924 NA
5-lug

[Paul]

Check your grounds from the battery to the body of the car and from the battery to the motor.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[jason c]

There are also some ground connections on the frame horns of the chassis behind/below the headlights.