82-911sc electrical problem
 

Need help/direction.

PROBLEM… quick flash on turn/hazard (all bulbs are good)

…occasionally while driving dash brake light comes on and tach goes crazy for 5-10 seconds

ELECTRICAL SHORT … but where do I start and how do I chase it?

I've owned this Porsche for 30 years!!
Thx.

Turn signal flasher relay is the likely cause of your rapid flash (was on mine anyway).
Get a volt meter and monitor it while you drive. I'm guessing a voltage spike is causing your Brake light/ tach problem. Time for an alt. rebuild i'd say.

agree with Pete...sounds like voltage regulator. they cause random elec. gremlins when failing.

Advanced auto sells a tool that plugs into your cigarette lighter that has a nice readout for checking battery voltage and charging conditions not very expensive either $15-20.