I got my car back with a new motor on thursday and I've been trying to put some miles on it to break it in. I was out driving around town for a few hours tonight and I started noticing something strange......

Whenever I'd brake and slow down, the add coolant, oil pressure, and battery charge warning lights would slowly fade on. The fading was directly proportional to the RPMs, and they would start to fade in only below 1200 RPMs. The lights stopped fading while I was slowing down after a bit of sustained driving at 2000 RPM's.

A few other symptoms are a slightly reduced cranking speed, and my windows don't seem to go up and down quite as fast as they were earlier. I have a feeling that it's just my battery losing power, or perhaps my alternator might be starting to go and not keeping the battery charged enough. Anyone have any ideas?

 

It sounds like you know where to start looking (alt./battery) I would also check the grounds on everything

 

Check your grounds.

 

Yep ... you've got the right idea. If your connections are good to the battery and alternator. I would borrow a charger, juice up your battery and see how the car behaves.

If it returns to normal for a bit I'd say new alternator.

Check around the internet for some rebuilt alt distributors. The local autoparts stores are way too expensive.

Hmm ... someone that was good with a voltmeter could also help you diagnose the problem.

 

Thanks for the ideas guys. I'll post on this thread if I get it figured out tomorrow.

 

If you've change the pulley, it will do this too!
On my 7 whenever I take off or breaking the lights will dim slightly.