Alternator questions
 

The alternator on my 85.5 944 appears to be dying. It shows right around 12v when running, and when the AC is on, it dips well below 12, and the belt squeaks like crazy (squeals when the ac isn't on sometimes, too), like the thing is trying to lock up.

It didn't squeal before I changed my AC compressor the day before yesterday, but it didn't charge any better before either. I don't think the belt is loose. How tight is tight enough?

It didn't do it before I changed the compressor, but.. When I was driving home the other day (AC compressor front seal died about a month ago) the bearing or something died in the compressor idler, and it engaged the compressor, causing it to turn when the system was empty. I wonder if it could have locked up, and burnt a place on the belt?

Sorry for my rambling, I'm just trying to identify the cause of the problem. What are your opinions?

I have a alternator off of a 82 928. Will it work on my 85.5 944?

Thanks!

Sorry for a double post, but does anyone know where I can get brushes for the alternator? Thanks!

Here's my take on your problem. Belt tightness: you should be able to push the belt along it's longest run 1/2 to 3/4 inch. If the belt wasn't replaced after the A/C seizing up you probably should have due to possible damage. When the A/C comes on and the squealing starts, that's slippage on the alternator belt. It won't put out the 13.8v you need to charge the battery. The brushes you refer to are part of the voltage regulator that sits on the back of the alternator. They're available everywhere, but here's the catch: if the new brushes don't sit well on the rings of the alternator due to grooves being worn into them, they may not function as well as they should. The VR is cheap and you could just replace it to see if it will work. If the alternator doesn't work after that, then start looking for a compatible replacement. First, I'd recommend a new belt and tighten it properly. Failing that, the VR next and then a new alternator. BTW, your alternator can be checked at some auto parts stores to see if it's not the problem (cheaper than replacing it).

Thanks for the info. I know what brushes are, nobody has them, though.

Automotive/Vehicle Brushes

I believe they can make/modify them for you if they don't have the exact size in stock. One of the guys on the Cruiser forum used them for fan motor brushes.

What it turned out to be... The belt felt plenty tight at the bottom, by the turnbuckle, but up top was a different story. I didn't notice it was loose up top because when I tightened it the other night, it was 10pm and my flashlight was dead. Looked at it today and could easily turn the alternator with a finger, and the belt was flopping. Easy enough fix. Now it doesn't complain with the ac on, blower on high, and the headlights on bright.

It seems to be all good now. Thanks!

So, the brushes are made into the voltage regulator? Cheap enough to fix.

A few months ago, I purchased a voltage regulator in order to repair the original alternator. Upon removal, I found the unit abundant of corrosion, rust, and general poor condition making my decision to replace the entire alternator an easy one. I'm not sure if the early and late models coincide but you're welcome to my VR.

Patrick

I think the voltage regulator is the same between the early and late.

What are you looking to get out of it?

PM me...