Faulty Alternator

911 Cab · 04-01-2003, 06:59 AM

Can just the voltage regulator be replaced on a 1989 Carrera?
The original Alternator was replaced 04/25/02 due to the lights going from dim to bright. 1 year later and less than 3000 miles, the lights at idle pulsate from dim to bright.

1989 911 Cab

Early_S_Man · 04-01-2003, 07:07 AM

Read this thread ...

Seat belt light = bad voltage regulator (follow-up)

masraum · 04-01-2003, 07:38 AM

I just replaced the reg in my alt, a local shop had it for about $30. The surface that the brushes ride on was very worn, so I'm sure I will need another alternator next time, but for now I have 13.5-14 Volts again. It's really easy to do since the reg is bolted to the back of the alt, and not actually inside like a GM alt.

Wil Ferch · 04-01-2003, 08:20 AM

I have a repair/replace article posted in the Pelican Tech area on Alternator/Voltage regulator....might be of some help.
--Wil Ferch

jazzbass · 04-01-2003, 10:33 AM

I found this to be a very simple and straight forward replacement.

This shows the back of the alternator (still attached to the wiring harness of the car). I circled the VR in red in this picture. There are two screws and two spade connectors - remove those, screw the new one on, reattch the electrical connections, and you're done. Be sure to mark the connections from the wiring harness to the back of the alternator (as you can see, I took pictures, too). So far, this has been one of the easiest things I've done on the car

.

geoff · 04-01-2003, 12:56 PM

HI, the only fault I see here is replaceing like with like. If it failed the first time, I would be wary about putting the same back.
Go here and have a look.
www.k3.com.au

Thanks

RoninLB · 04-01-2003, 01:57 PM

Quote:

Originally posted by geoff
HI, the only fault I see here is replaceing like with like. If it failed the first time, I would be wary about putting the same back.
Go here and have a look.
www.k3.com.au

Thanks

that K3 alt is $750.. JW posted a good alt. that is cheaper than the Valeo.. and Valeo is a good unit

jazzbass · 04-01-2003, 02:00 PM

Quote:

Originally posted by geoff
HI, the only fault I see here is replaceing like with like. If it failed the first time, I would be wary about putting the same back.

Not sure exactly what you mean... the VR also contins the bruses for the alt, so its a wearable item. The brushes wear out, R&R the VR, and you're done. 9 times out of 10, overvoltage = bad VR, undervoltage = bad alternator. In the case of overvoltage, by replacing the VR, you're fixing the problem, not a symptom of the problem.

RoninLB · 04-01-2003, 02:24 PM

anybody know if you can "full field" one of these internal regulators like you can the old style?

geoff · 04-01-2003, 06:23 PM

Hi, the $750.00 is Australian. About half that in US$.
If a Valeo reg has failed after a short term, why put the same one in again?
Try here
www.**************

john walker's workshop · 04-01-2003, 06:53 PM

if the commutator is still smooth, which is unlikely, a new "same type" reg should last pretty long. it did last 14 years, right? the brushes in the reg chew up the comm, so if it's grooved, then it won't last long. the comm is very thin, and i've seen many that wore all the way thru. so take your chances if just the reg is replaced.

Wil Ferch · 04-03-2003, 07:06 AM

A major problem that most people don't realize is that with our "garage queens" that don't get daily use..it is possible for the alternator/VR to act as a quick charging unit...rather than a "topping-off" unit it was designed for in the first place. Meaning?; these things tend to wear out sooner under these conditions of recharging a battery that may have sat for weeks. I've replaced my stock VR (Paris Rhone part) with a German made HUCO part on the first failure...perfect match...but the metallic ribbed heat sink on its backside is much larger than stock. Having the VR buried deep inside the recesses of the alternator/fan structure makes hot-soak after shut down an issue, too.
---Wil Ferch