2002 Silverado battery light on

[Black02Silverado]

I'm thinking this is an alternator issue but wanted to get other ideas.

My 2002 Silverado has 160k miles on it. This is the original alternator. When I first start it after it sits for a few hours, basically when it is a cold start. The battery light comes on and stays on until I bring the rpms up. What is also weird is I have a ScangaugeII installed and the display will not come on until I bring up the rpms.

When I first start it, the volt gauge on the dash is showing 10vdc. When I bring the rpms up it goes up to 14.2 and the ScangaugeII comes on and it shows 14.2 as well and the battery light goes out. From there on out it runs fine. No other issues with the light coming on. Driving it around the ScanguageII shows 13 to 14vdc.

All my electrical connections are clean and tight, as well as all the grounds.

Do you think this is an issue with the regulator inside the alternator?

I was going to pull it off and have it rebuilt. Not a fan of getting one off the shelf at AZ,AA, CQ or O'Rileys.

[00Silverado4x4]

Sounds like a failing alternator. I'd pull it and have it tested to verify and repair/replace as you see fit.

[Black02Silverado]

Going to pull it. A place here said that it sounds like the slip ring is worn. They can rebuild it for $86 with a one year warranty. Just was curious and AA has one for $176.

[Black02Silverado]

Took the alternator off and had it rebuilt. The place tested it and it showed good. But when I picked it up he said it was amazing that it was putting out any power at all. The brushes were gone and the slip ring was shot. So it is all back to new with new bearings and all and out the door for $75.

Not to bad since a new Delco at Advance Auto was showing $174.