71 E turn signal problem

[mhurwitz]

On my 71 E the turn signals work fine, but when the turn signal arm returns to neutral the emergency flashers start flashing and won’t stop. I have replaced the emergency flasher unit and also the flasher relay. I also took the steering wheel off and the cover over the turn signal arm to clean it and make sure it was free of any grease or dirt. The problem still exists.
To add to this weird problem…..when I pull up on the E brake….the red light flashes on the gauge like it’s supposed to….but both turn signal lights flash also.

Any suggestions would be appreciated.
Thanks,
Mark

[PeteKz]

Mark, problems like this are usually caused by poor grounds, or sometimes by wires with insulation that has rubbed through and is causing a short circuit. After 50+ years, one or the other is likely. There are lots of similar discussions in other threads.

Do you have a wiring diagram? If not, first step is to get one, either by copying one that someone has posted in these forums or somewhere else online. Better yet, get a printed version from one of the online vendors. Then you will have to start tracing circuits with a volt/ohmmeter. There aren't any quick and easy answers, as you should know from having replaced several parts already.

Speaking of the parts you replaced: Did you use known good replacements?

One other thing to do at this age: replace your fuses! These old bullet fuses have a small strip of copper or tin exposed to the air. After many heat cycles and exposure to moisture, they develop cracks in that strip that cause intermittent or strange electrical problems. I have solved weird electrical problems by simply replacing the fuses if they are 10+ years old. Over on the Mercedes List, we call this the "Marshall Plan" after the distinguished gentleman who advocated it.

[Schulisco]

+1 for the ground issue

Wiring diagrams:
https://classickabelboomcompany.com/wiring-diagram-porsche/

[E Sully]

A couple of diagrams I made if it helps.



A thread on function.
71 turn signal function

[mhurwitz]

PeteKz and Schulisco,
Thank you for the input and also the wire diagram. I will get to work on it and report back whether I’m successful or not.
Mark

[mhurwitz]

E Sully,
Thank you for the diagram
Mark

[Schulisco]

Here's a diagram of the ground connection points

https://forums.pelicanparts.com/porsche-911-technical-forum/384164-cant-find-ground-engine-compartment.html

[Schulisco]

more detailed from a 3.2 Carrera, your '71 may not have all of them?



And use a good contact spray, not that stupid WD40 which evaporates after short time and gets worthless

[mhurwitz]

I cleaned all grounds and replaced all fuses.
Problem with turn signal still exists.
Backing up about a year……everything was working fine with flashers and turn signals.
I have owned this car since 1978 and know its characteristics pretty well.
One day I noticed that there was a clicking sound coming from behind the guages. I determined it to be the flasher relay.
I bought a new flasher relay from PP….and the clicking went away, but nothing worked properly.
I ordered another different brand of flasher (genuine OEM) and the clicking stopped, but nothing worked as it should.
A friend of mine just gave me 25 misc flasher relays and I tried them all.
I found one that duplicated what my original one did…..everything works as it should….but there is a continuous ticking from the flasher.
Just can’t figure out what is making it click all the time.

[ed mayo]

Try unplugging the two wires at the master cylinder switch.

[Schulisco]

Originally Posted by ed mayo

Try unplugging the two wires at the master cylinder switch.

That will make the brake lights won't work any more?!! Really??? Curious for your explanation.

[ed mayo]

The brake light switch is on the brake pedal. The switch on the master cylinder is for low brake pressure and hand brake applied. By unplugging those wires you can determine if that is the problem area.

[mhurwitz]

Originally Posted by ed mayo

The brake light switch is on the brake pedal. The switch on the master cylinder is for low brake pressure and hand brake applied. By unplugging those wires you can determine if that is the problem area.

I unplugged the 2 wires on the master cylinder and that took care of the clicking. All lights….including brake lights work fine.

Thank you!

[mhurwitz]

After reading more of the posts, I see that John Walker suggests doing this also