Griff 500 Alternator/electric probs
Griff 500 Alternator/electric probs
Author
Discussion

john sumner1

Original Poster:

28 posts

248 months

Wednesday 2nd April 2008
quotequote all
I've had a problm with the voltage output on the alternator. The gauge reads 12 volts (Should read 14 v plus), and when the alternator was tested on the car whilst the car was running, also registered 12 volts, so I thought a new alternator would solve the problem. Not so! Even with a new alternator it still registers 12 volts at the gauge and I noticed neither the ignition light nor the oil pressure light came on when I turned on the ignition key. The car runs ok, has normal oil pressure, and starts first time every time but, I'm worried that if I take it on any sort of a journey then the battery will run flat.

Does anyone have any suggestions?

regards

John

spend

12,581 posts

281 months

Wednesday 2nd April 2008
quotequote all
Sounds like your dash may not be feeding the gauges / leds (warning lights) 12v. The alt needs 12v on the sense wire to get it started (energise the field coils) wink

Dave

john sumner1

Original Poster:

28 posts

248 months

Wednesday 2nd April 2008
quotequote all
spend said:
Sounds like your dash may not be feeding the gauges / leds (warning lights) 12v. The alt needs 12v on the sense wire to get it started (energise the field coils) wink

Dave
Thanks Dave

You are responding as if I know the feintest thing about electrical wiring - I don't! can you explain what you mean by "The alt needs 12v on the sense wire to get it started (energise the field coils)"

cheers

John

spend

12,581 posts

281 months

Wednesday 2nd April 2008
quotequote all
Awkward sod! hehe

If you have a multimeter, connect to a good ground the black prong and the red one to the green/brown (IIRC - single thin wire & not black) connector/wire on the back of the alternator. When you (or your glamorous assistant - can I still say that wink - if you are gay I really didn't mean it BTW [just in case UF is still stalking]) switch the ign on you should see 12v on your multimeter.

If you don't it is quite likely that you need to pop the dash off & look for a break in the proliferation of green wires (prob where a load are bunched together).

Dave