Porsche Enthusiasts Club Forum

Since just after the MOT my rev counter had been playing up, just kinda going where it wants, the MOT guy had a quick look on the retest and he thinks the voltage regulator on the alternator has gone. Not yet found out the cost of this :-[ now though my stereo has started switching itself off when it wants as well and the new one today is resetting itself as if it has lost its connection to the battery all together. Anyone know if the alternator would cause that as well or am I looking at needing the electrics needing sorting as well?

no-one???

You need to check the charging rate, it might be that its overcharging. I would suspect that if it is you would be able to smell the acid when you open the boot.

It could well be the regulator has died. Unusual to affect the rev counter though normally it blows bulbs etc. Do you have a multimeter to see what it is doing to the battery? You should see around 12.9-13.2 volts.