I want to fix my old alternator, O'Reilly test said that the diode was bad.

The alternator is GM p/n 20862829. Valeo part number FG12S019. Google can't find the rectifier/diode assembly anywhere. I'm not sure if I could get the old assembly off anyway.



It looks like I would have to open the clips(crimps) on each of the 6 leads from the stator. Then the assembly might come off. It looks like there are 12 diodes?

I'll probably have to find a shop to rebuild the alternator, but I was hoping to do it myself. But I can't even find the part number.

 

I can see why you want to replace the parts yourself but is it worth the aggravation and possibly other parts are on the way out? At 11 years old can you trust the bearings? Stator windings?


A new one from GM, SS specific

A new one from RockAuto or the rebuilt for 1/2 the price, but be aware this part numbers are not SS specific
Except the Valeo 849111.

 

This is the first result in a youtube search for "hhr alternator rebuild"

 

But is the SS alternator the same? Not according to the GM folks it’s only in the 3 years of the SS version of the HHR

 

Ok, so the rest of the story...

Mid December last year, I installed a new OE alternator, ordered from an Amazon seller. Wasn't packaged very well, but the alternator looked fine. Well, it squeaked a little for a few months, then the squeak pretty much went away.

Fast forward to a month or so ago, I removed the coolant recovery hose from the filler neck to see if the 11/32" hose that I had would fit(not quite). Well,, I forgot to reconnect the hose for awhile, and lost some coolant. We know where it drips, onto the alternator.

I discovered my error and reattached the hose. But I had a time getting the coolant topped off. Somehow, the hose clamp on the radiator hose at the filler neck was also loose, leaking coolant. I don't know how it got loosened, or for how long.

So I got the coolant topped off, burped, everything looked good.

Then the squeak returned, except now it was a much louder squeal. I tried to get an alternator from hellshotrod, but he didn't have one for an SS. So I figured I'd just get the old one fixed.

Then I thought, maybe it's something else, maybe the tensioner. So I removed the old tensioner from my old LNF that's on the engine stand,and installed it on the new engine.

The squeal was gone! Fixed it!

After a weekend in Las Vegas, with no squeal, returned home on Sunday. When I started the car on Monday, the squeal was back, not quite as loud.

I just can't tell which of those 3 pulleys are squealing, or maybe it's the belt? The tensioner that I removed, and the belt are almost 20 months old. The alternator is almost 11 months old. The compressor and currently installed tensioner might be original.

 

If the alternator was exposed to coolant, I would not trust the bearings, and replace the alternator.