HELP!: Instrument panel turn signals both ON and static

[EricZman]

My 1977 Porsche 911S just woke up this fine morning with a problem.

When I turn the key to the furthest position, and while starting and driving her, BOTH turn signals on the instrument panel are statically ON.

Also, when I pull the turn signal lever for a left turn, the RIGHT instrument panel signal light flashes while the left one stays solid ON, and vice-versa.

The turn signals outside the car work perfectly fine, so no issue there. The problem is at the instrument panel.

Anyone have any clue how to fix this? I was going to take her to be inspected today and get her titled, but ran into this problem.

All the fuses work fine.

We did have one helluva storm last night (she was covered, but not garaged) and the antenna broke thru the car cover, so some water *may* have leaked thru that small hole, but whether or not this has any bearing on the problem, I do not know.

Thanks for everyone's input and knowledge! This is my first Porsche and I'm excited to get her fully legal to drive (my temporary tags expire October 7th).

Thanks again!

[Charles Freeborn]

I've got the same thing going on. Plan to troubleshoot today. These things frequently are ground wire issues from turn signal housings (plalstic) to chassis, etc. Rainstorm may be coincidental, or could have inhaled some water into light housings and so on. There are clusters of wires behind headlights too.
I'll report back when I've had at mine.
-C

[HawgRyder]

Yup...grounds.
Start with the easy ones ...progress to the difficult to get to.
Bob

[EricZman]

Could it be ANY ground wire that is causing this problem, or only ground wires that deal with turn signals? I'm not very electrical-savvy, so I need more info than "ground wire is the problem" please

[HawgRyder]

Eric...try the grounds in front and back lights first.
When you put the signals on...and you get the problem...it says to me that the bulbs are not being grounded at the sockets.
When this happens...the circuit is forced to take the path of least resistance to turn on the light...etc.
When dealing with electrical problems...the ONLY common item is the ground!
So...check grounds first...after all..the car is old...and corrosion can happen...
Bob

[EricZman]

Ok, the problem went away (it goes in and out) so I pulled into the nearest inspection station -- and now the brake lights and reverse lights aren't working!!! Good gravy, this is maddening.

Pulled off the driver's rear light cover and cleaned the contacts (bulb filaments were fine), didn't do the right side since there was nothing visibly wrong with the bulbs on the left. Still nothing.

The guy at the auto parts store said brake switch, but I don't see how that would affect the reverse lights.

Any thoughts?

[timmy2]

Link to ground location post.... your '77 should be similar.
Location of ground straps

[EricZman]

Ordered the brake switch today. From the wiring diagram I found, it does appear that the reverse lights would be affected if the brake switch stopped getting power.

Hopefully not too hard to replace. We'll see!

Still need to check for ground-outs because the original problem still goes in and out... so weird.

[EricZman]

Well, replaced brake light switch finally, and got that working again, but reverse lights are still out.

Also, still have the original problem.

The only light I have out is a side marker light and I tried to replace the bulb, but still nothing, so I have to figure that out.

Bought a new turn signal/hazard relay switch (a cheap one, unfortunately) but it acts like not enough juice is getting to it to make it blink. It tries to blink once, then both turn signals on the dash light up simultaneously and the hazard light won't come on at all.

At least with the original relay, the hazard light would still work and the turn signals would work, just the lights on the dash would blink in reverse.

But recently, on the original one, one of the contact blades was charred a little so I scraped the charring off and scraped the other blades to hopefully make a better contact -- and now the hazards won't work!

This is driving me insane.

So, now I've ordered the actual Porsche relay ($60+), and in the meantime I'm going to try to figure out the side marker bulb issue and any other potential grounding issues. Blech!