porsche 928 RI

Hello all, i am trying to diagnose why the gear position indication light does not work ( it is an 86.5 automatic) i have looked through the forums and have not found much on the topic, yesterday the light illuminated for the first time in the 2 years i have owned the car. however after a cycling of turning the car off and on, it has now decided not to work. where are the switches located for the light? bad connection? help would be greatly appreciated

thanks
-Liam

SQLGuy

My first guess would be a worn out ignition switch. Try wiggling the key around and see whether the light flickers.That indicator seems to be the first thing to go when the ignition switch contacts get worn. If this is the case, it's actually not too expensive a part, nor is it that difficult to replace.

Second guess would be bad contacts, broken traces, or cracked solder joints on the flexible PCB of the instrument cluster. That kind of problem also often leads to flaky readings from the fuel gauge, tach, speedo, etc.

WallyP

First thing to try is cleaning the electrical connector located in the forward right corner of the spare tire well. The switch is located on the transmission where the shift cable goes into the housing.

porsche 928 RI

after some fiddling around it turns out it works when the interior light is turned on, must have some funky wiring to go through

Speedtoys

The fuse for it is shared..10 or 24?

dcrasta

Have you done your grounds, as someone said, the rear tire well has a plastic triangular cover with wires going into funky connectors. There are also to grounds there (brown wires are grounds) . Clean the grounds, reset all the wiring you find in the rear hatch. That is how mine eventually worked.

With your issue, it sounds like a ground issue to me. If you turn the interior light on that may create a new ground path. When you have erratic operation of electrical parts (things work when something else is turned on) it can often indicate inadequate grounds.


tl;dr


-Read the FAQ. First thing mentioned is cleaning all the grounds.

Mongo

I am dealing with the same thing right now. My lights work intermittently unless I turn the headlights on.

My fuel gauge is also flaky too; could this be ignition switch related also??? THat's the only needle that jumps.