Battery Warning Lights Come on

[andy900se]

The battery warning light started to come on intermittently this week. I’d suspected that the belt to the alternator was loose so I tightened it and now the lights on full time. What do the experts think, time for a new alternator?

[900t]

Is it overtightened? Should be around 2 1/2mm deflection in the middle of the alt and water pump (or so).

[ShadowWorks]

Maybe not a new alternator but a new regulator, its a small part thats on the back end of your alternator and has 2 carbon bush that may have worn down.


a $15 dollar repair i think, if this is not at fault check the wires on your alternator and the ground cable, after that check your battery when your car is switched off, it must be over 10.5 volts and if in good health would be 12.+

The deflection i would say should be about 1 inch maybe less, never over tighten the belts unless you want to damaged the crank pully.

[cdaly]

Instructions for replacing the regulator are here: http://www.saabcentral.com/forums/sh...ad.php?t=53542
Instructions for replacing the carbon brushes within the regulator {often this is all that's wrong} are here: http://www.saabcentral.com/forums/sh...ad.php?t=30596
and why you might want to have the alternator rebuilt anyhow is here: http://www.saabcentral.com/forums/sh...ad.php?t=27280
and a troubleshooting guide here: http://www.saabcentral.com/forums/sh...ad.php?t=30908 Both alternators I had rebuilt had plenty of wear in their slip-rings...

[andy900se]

Thanks for the advice. I had overtightened it so in the end I had my local garage swap the alternator for a recon unit and all is now fine. Probably good for another 130,000 miles.

[drsib]

Originally Posted by ShadowWorks

Maybe not a new alternator but a new regulator, its a small part thats on the back end of your alternator and has 2 carbon bush that may have worn down.

i had that same problem, and i took me for ever to figure it out!! lol

[Matthew]

I have flat battery problems on my car. Background: connecting the battery up in reverse polarity fried something in the alternator.

I replaced the voltage regulator, but alternator wasn't charging. I replaced the alt with a spare and now it's charging but the battery gets flattened. Could a faulty voltage regulator cause the battery to discharge to itself through the alternator?

I got the VRs mixed up so I didn't know which one was off the original alternator .

Also: is it possible to DIY repair the alternator's bridge rectifier? That's what folk mean when they refer to the "diode pack", right?