Alternator Light stays on 5 minutes

hooligan6a · Post by **hooligan6a** » Sun Dec 26, 2010 12:55 pm

I have a 1981 VW diesel pickup and just had the Motorola alternator rebuilt,
Now the Batt, light comes on when I turn key on but it stays on for about 5 minutes with the engine running. Shouldn't go off when the engine starts??

coke · Post by **coke** » Sun Dec 26, 2010 12:57 pm

Does it go off if you blip the throttle?

hooligan6a · Post by **hooligan6a** » Sun Dec 26, 2010 1:20 pm

Only if it runs for 4/5 minutes.

hooligan6a · Post by **hooligan6a** » Sun Dec 26, 2010 1:21 pm

I forgot It does have a new battery.One week old.

joat · Post by **joat** » Sun Dec 26, 2010 1:40 pm

go back to the shop and have them test it ... maybe sticking brushes.

Vincent Waldon · Post by **Vincent Waldon** » Sun Dec 26, 2010 3:42 pm

Just to be really clear... you can blip the throttle over 2500 RPM and the light still stays on... you have to be actively driving for 5 minutes or so... working thru the gears.. until the light goes out?

Ira B · Post by **Ira B** » Sun Dec 26, 2010 4:51 pm

I have the same set up and awhile ago the light seemed to be taking longer/higher revs than usual to go out. SHortly after the alt kicked the bucket.
With the new alt thew light goes out at about 1500 rpm (est.) or after a min. or two.
I suspect if yours is suddenly getting your attention it may be on the way out.