sorry guys for the dumb question but i can't find it anywhere online.. where is the voltage regulator for my audi s4. I think that is what im having the problem with. The battery light on my instrument cluster is on.. and my battery power pegs up and down...

 

Your voltage regulator is built into your alternator. Same thing happened with my car, your going to have to replace the alternator.

 

did you have to pull the front end off to get to the alternator and replace it?? im doing timing belt and belts soon. so im already taking the front off..

 

no need to take the front end off, although I guess if you were doing it all at the same time, then sure it would probably make the job easier.

repair manual states that you need to remove air intake duct, lower noise insulation panel, remove belt, remove hose from intercooler, detach starter/alternator cables from frame rail, disconnect wires from alternator and pull it out. It also states that you can replace just the voltage regulator inside the alternator if you so desire, requirestaking the alternator apart.

Shawn

 

alright nice. well i pulled the whole front off.. goign to pull the alternator out and check it out and the regulator.. are there any bad signs that i should look for?

 

possibly look at the surrounding electrical components for black burn marks if you are taking the alternator apart. That would cause a shorted regulator to spike if its half working but only allowing the electricity to flow through and not be "regulated"

 

Take it somewhere and have it checked. PartsPlus or autozone should be able to tell if theres a problem with the regulator or rectifier bridge

 

yeah i got it out and checked it at autozone... something popped out on the computer saying 90amps.. and its supposed to be 120amps...
Im still going to take it to another place and get it checked out...
does anybody ahve the DURALAST alternator in their car? its like 190$ with a lifetime warranty.