alternator fix/replace & Fan and shroud ?

masraum · 08:51 PM

AAaah! Man...

So I finally got around to putting the voltmeter in tonight and thought, cool, when I hooked it up and turned the key on and it jumped to 12 V, then I started the car and watched it hit 16+. At that point I wasn't thinking "cool" anymore, but figured I would run in, grab the Digital Multimeter and verify the readings. Sure enough, nearly 17V when revving the engine. Crap!

So now I am wondering, what to do, new alternator $400-$500, rebuilt alternator $200, or get mine rebuilt $70-100. (I'd love to do it myself if I could get the parts).

What does everyone think?? I'd prefer the new, but it would be hard to justify that since I'm not rollin' in dough.

Number 2, a while back I noticed that the fan has scraped the shroud at some point (before me I'm pretty sure) and now there are some messed up fan blades (magnesium must react weirdly to heat, because it looks like some of the blades started to inflate like popcorn. I think it would be best to replace the fan, housing, and deflectors behind the fan (I can see some cracks bending). Does anyone have any idea how much another (used/salvage part might run?? I guess I'll be on the telephone tomorrow.

Crap, crap, looks like I've got some parts going on the plastic.

heheh, I guess that explains why my headlights and dash lights are so bright. No complaints from me in that dept. heheh

Argo · 01-27-2003, 09:02 PM

It's most likely the voltage regulator, not the alternator. Good news for you - it's lots cheaper than the alternator and easy to replace (once the alternator is removed). Don't enjoy those bright lights too long as they'll cost lots if things start melting/shorting, etc. - fix this before it really costs you! As for the fan/shroud/plastic - if you want used call partsheaven or Ian's europarts. A google search will get you the info you need. Don't know the cost but they'll probably use the $ you save from not replacing the alternator (plus a bit more).

Argo
88 Targa

Wil Ferch · 01-28-2003, 05:50 AM

I did an alternator / voltage regulator R&R that appears in the tech write up section of Pelican as well as Rennlist. Should answer your questions. I also think it's your regulator...about $150 from the dealer and about $50 from Porsche parts places.
--Wil Ferch

Rick Lee · Rick Lee's Garage

I just went through the new alt. and new fan housing fiasco. If all you need is a voltage regulator, that's a cinch and a cheap one. But if your fan is rubbing, that probably means your fan housing is cracked, which is often caused by an overtensioned belt. When you pull your alt. out, look at the rear fins of the fan housing. I needed one and got two wrong ones sent to me and two correct ones that were cracked. They are $500 from the dealer and they ain't easy to find used. I even have one of the wrong ones I was sent on eBay right now. Sorry - it's for an SC. I have heard that you can use an older fan housing if you have the rear lip milled down to 7mm thick, which Vertex suggested to me for $120. Otherwise, the fan will stick out too far. Finding the correct fan housing is a real b!tch. Don't reinstall one that's cracked. And don't overtension the belt!

masraum · 01-28-2003, 06:36 AM

Yeah, the fan isn't rubbing now, but it obviously has at some time. I went through the PO receipts last night after I posted and discovered that the PO had a new alt put in in 1/96, then had it replaced again 2/96 under warranty, then again in 3/96, then for the last time in 9/96. I suppose since it was recently rebuilt the bearings, etc... should be in good enough shape. I just didn't want to replace the VR if there were other parts that would be wearing out soon, but, if you all think replacing the VR is good enough then $56 it is, now to find a fan...

Rick Lee · Rick Lee's Garage

If the fan housing is cracked, it's probably rubbing, which will wear out the alt. pretty quickly. You probably won't hear the rubbing unless you take it all out and spin it by hand. Even then, you have to remember the belt will be exerting a downward tension on it.

Sean Hamilton · Sean Hamilton's Garage

Knackered bearings in the alternator can also cause the fan to rub on the inside of the shroud and also wear out the alternator. If rebuilding the alternator always replace the bearings too.

Jdub · 01-28-2003, 07:22 AM

Be sure to pull your battery and bench test it at a Sears or equiv. When I had my alt. rebuilt (new reg. too), I went ahead and spent the money on a new battery and made a point of cleaning all of the ground straps: negative cable, under engine, etc.

Just a thought. How old is the battery?

John

jmohn · jmohn's Garage

Can't help with the fan/shroud problem although, as someone pointed out, bad bearings in the alternator could be causing the fan to rub. I agree it's probably the regulator that's "gone south" but as you have to pull the alternator to replace the regulator (I'm assuming you have the newer internal regulator model alternator) I'd find a GOOD local auto-electric shop and have the alternator rebuilt too. Let them do everything, total cost (with a new regulator) should only be $150-$200. Rebuild on mine (older externally regulated) was $70 two years ago, completely refurbished, new bearing and bench tested. Of course, this was a shop I've used for years and trust.

Jerry M
'78 SC

masraum · 01-28-2003, 08:01 AM

I noticed the rubbing a long time ago about the time the old belt wore out. I believe the rub marks etc are from when the PO had the alt replaced, likely his bearings went bad causing the rub marks. I have had the belt off and felt no slop in the bearings, and over a period of 3 months can see no change in the rub marks.

The battery is relatively new, probably less than a year, and is a big monster. I'm almost hoping I need to replace it soon so I can go with a gel battery and loose the weight, but for now it's not having a problem. I would like to replace the bearings since I have the thing apart, is there anyplace that I can buy the bearings?

GT911 · 01-28-2003, 09:44 AM

masraum,

I bought a new VR a couple of weeks ago for $25, from A&B auto electric, they are at 9225 Manchester St. (713.928.3286) on the south side of the ship channel bridge.

I’m pretty sure they would have your bearings as well, and they’re just a short drive up the road.

masraum · 01-28-2003, 09:52 AM

Sweet, that is not far at all. Thanks tons!!

Sean Hamilton · Sean Hamilton's Garage

Quote:

Originally posted by masraum
..........I would like to replace the bearings since I have the thing apart, is there anyplace that I can buy the bearings?

Make sure that the replacement bearings are of the highest quality.
I learnt the hard way - there is some crap cheap stuff out there.
The Auto Elec should be able to source top quality bearings as part of the rebuild service.