Alternator Question (3.2 internal VR Help)

[myrddin]

I have a 3.2 in my car and just lately the battery light has been flickering an idle but when you accelerate it goes away.... Sometimes it stays off and sometimes it comes back on at low idle. Any thoughts on what the deal is... if it was a short or bad contact wouldn't it do it all the time... Could this be the start of a bad voltage regulator? And last question.... can we rebuild the VR's our self or would I need to have someone do it... or replace the alt. all together????

I just cant win.... I thought I had it all knocked out so I could start on cosmetic things and yet another mechanical thing starts giving me trouble....



Advice

[Barrpete]

It could probably be a lot of things. A quick & dirty check is go to the local Autozone and get one of those voltmeters that plug in the cigarette lighter for $20. Not super accurate but it will give you a pretty good idea of the voltage output. Then troubleshoot from there.

You can't rebuild the VR, but you can replace it. Pelican sells them. You do have to remove the alternator to get to it though. There is an excellent article in the Tech Section on this by Wil Ferch.

[myrddin]

thanks.. I have a meter I can use and will start looking at it tomorrow... The thing is I was told that rebuilding the altinator was a bad Idea and that it would just fail agn... Is that true. I guess I will need to see what I have and decide what to do.

[Barrpete]

On the contrary you can have the alternator rebuilt. I just did this job on mine earlier this summer. The VR is mounted externally on the alternator so it's easy to replace - once the alternator is out. Removing & reinstalling the alternator is a fairly tedious job so while it's out you might as well rebuild it - or at least have it checked out. It cost me around $100 to have mine rebuilt vs. about $500 for a new one.

[myrddin]

what parts do I need to replace my VR on a 3.2? and if my battery light comes on and stays on unless I accelerate would that be the deal here? Some days its off and some its on???

[myrddin]

Is this all I need?

911-603-913-01-M262

Voltage Regulator, internal type, 911/911 Turbo 1982-89 Brand: Valeo

[Barrpete]

Originally Posted by myrddin

Is this all I need?

911-603-913-01-M262

Voltage Regulator, internal type, 911/911 Turbo 1982-89 Brand: Valeo

That is the part. For an excellent step by step description of how to do this job check out Wil Ferch's article in the Tech section. Read it thoroughly before you start, it will make the job go much easier.

http://www.pelicanparts.com/techarticles/911_volt_reg_replace/911_volt_reg_replace.htm

[myrddin]

OK guys.... I got the VR and installed it and it worked for a day and now my red light is back solid pretty much.... Any idea? Also I just cant seem to beat some of these things.... I hope someone can help me out...

I am looking for a good alternator... I am pretty much about out of money and this car is about to make me want to sell.... I want to enjoy it not work on it all the time...


Help

Also when i installed it and put the fan back in the pully rubbed on the fan so I had to take it back apart and try agn... It is so close in that area... I would think there should be more clearance..

[n8marx]

A new voltage regulator and new brushes cured this problem for me.

[450knotOffice]

myrddin,

Interestingly enough, I just had this problem crop up in the last week, and it was finally resolved today, after removing the alternator twice.

I was out with a fellow Pelican last week and after returning to the car, it would not turn over. The battery was just too weak. We were able to push start it however, and the ride home was uneventful. That evening, I hooked a multimeter to it and noted that there was no charge to the battery from the alternator. I was showing about 12 volts instead of the more usual 13.8 to 14.

Before pulling the alternator, I decided to inspect and clean ALL of the big grounds. For the most part, they were fine, but I replaced the battery Negative cable anyway because it was looking old. I checked the ground strap from the transmission to the chassis and that was good and tight. I even pulled the known good battery from my 996 and swapped it into the Carrera. I ended up with the same 12 volts, which confirmed that my alternator was not doing it's job. Also, while the battery was out, I hooked it up to a trickle charger to be brought back up to top health.

I pulled the alternator out the next day and checked all of the wires inside and they were basically fine too.

A few days later, when I had time, I sent the alternator off to be rebuilt at a shop that another fellow Pelican had recommended (and which was very, very close by). The guy had the job done in a few hours and I picked it up the next day. He said he replaced the Voltage regulator and the brushes and obviously had cleaned it up to look like new. It cost me $125, which I consider a good price. Anyway, I re-installed it, buttoned everything back up and fired up the car. I checked the voltage again and all was good - 14 volts.

However, all was not good for long. The next morning, early (I mean dark early), I fired the car up and noticed a very faint pulsing glow coming from the alternator light, which went out (mostly) above about 2000 RPM. Damn. I drove the short distance I needed to and left the car until the afternoon. It started just fine and got me home. I immediately hooked up the multimeter again and found that it was back down to 12 volts again.

So, late last night, I pulled the alternator out again. This morning I brought it back to the guy and explained what had happened and he gave me a somewhat dumbfounded look and said "let me bench test it and see what's going on" About 20 minutes later, he came back with a smile and said (somewhat sheepishly) that he'd somehow missed a bad diode, so he replaced it right then and there and did a beautiful job of soldering in the new one. He handed it back to me with a smile and off I went to re-install it. After the re-install (again), I checked the voltage and was relieved to find that the alternator was putting out about 14 volts again and the warning light on the dash was completely out - even at idle.

Interestingly enough, I just read a long thread by another guy who had rebuilt his alternator and he ended up having basically identical symptoms to what I was having (and you). He was stumped and dismayed. Anyway, long story short, he found out that his alternator had a bad diode, just like mine.

Here's the thread (his resolution is in the middle of page 2):
drops under 12 v. with New Alternator

The point of the story is...make sure the rebuild shop carefully checks your diodes. If there is even the slightest hint of trouble with one or more of them, have the offending diodes replaced. It seems that so many shops simply take the units apart, bead blast them clean, check the windings, replace the brushes and voltage regulators, put them back together and call them good. I'm getting the feeling that many shops don't seem to really test the diodes properly. They should.

[myrddin]

450knotOffice.... thank you for your post... I can only hope that is also my problem... you explained it just as I am seeing it with my car... I will make a few calls to se about a rebuild... Or I know of someone who will sell me a used but 100% working one for 95....

You guys are a lot of help... I just hope I can get past this and enjoy the car....

Thanks and I will let you know if it worked.....

[Lorenfb]

"It cost me $125, which I consider a good price."

Good price? What does that mean when the part is junk? (Note: Parts alone cost $90+.)
That's what happens when one buys on price and uses unkown sources.

"However, all was not good for long. The next morning, early (I mean dark early), I fired the car up and noticed a very faint pulsing glow coming from the alternator light, which went out (mostly) above about 2000 RPM. Damn. I drove the short distance I needed to and left the car until the afternoon. It started just fine and got me home. I immediately hooked up the multimeter again and found that it was back down to 12 volts again."

So much for those low cost rebuilders!

Now keep those "fingers crossed" while driving.

A lot of headaches could have been avoided, i.e. using junk parts, by buying from Pelican Parts (Note: SC is not a Pelican supplier.)
Does that rebuilder have a free Porsche web site or sponsor this one???????