Red light off death / Alternator Voltage Regualtor Problem
 

Hi,

Just got my car back from it's annual service at a Porsche centre in the UK and on the way home the red light of death started winking at me everynow and again.

I can't seem to get it to come on permanently, only when dropping down the revs when driving.

The car is now in the drive and it won't light up.

BUT

Digital volt reader on the battery says: -

12.3 - Engine off
11.76 - Engine running (No red light)

I have had a 'fiddle'with the wires in and around the VR to check there are no loss wires, all appears to be ok.

The '101 Projects..' book states the following about a non red light: -

Alternator indicator lamp does not light when the ignition key is turned on.

• Alternator bulb is burned out
• Regulator has failed
• DF wire is disconnected or broken from alternator
• Alternator has failed and internal windings are open

Any ideas...

im no expert but - did they mess with the belt? they may have left it a little loose and now its slipping, which is why its coming on and off. did they get grease on it? ide start with examining the belt for tension, correct amount of shims, grease etc...

oh...i didnt grasp that you had a no light situation with the key turned.... cant help you there. sorry. someone here will be able to help im sure so stay tuned

UPDATE:

I have had a new alternator fitted. It is the internal regulator type.

Strange thing is that the red light on the dash is constantly on now. The battery is charging fine when the engine is on. (14v)

Also the idle seems to have gone to pot!

Any ideas on the red light being constantly on?

Regards,

Simon

Check these two threads for wiring / lamp issues when changing from externally regulated to internally regulated alternators:

http://forums.pelicanparts.com/showthread.php?t=216543&highlight=Alternator+exter nal+Internal+Regulator

http://forums.pelicanparts.com/showthread.php?t=172131&highlight=Resistor+Lamp+Al ternator

Great, thank you Deanp. Looks like I need a resistor fitted.

Regards,

Simon

Could also (possibly) be a bad diode in the alternator.

Could also (possibly) be a bad diode in the alternator.