Yeah, she would probably disagree.:rolleyes:
Sounds like you have a good plan.

After reading this thread I had to ask myself " What is the advantage to an integrated alternator if the repair is so much more difficult and costly if it is just the regulator? :confused:
Good luck with the fix, Todd

Bob,

There is NO 'advantage' to the owner of an alternator with built-in regulator! Porsche was merely lowering production costs like all of the other mfrs.

For me ... the 980 Watt Marchal alternator and separate regulator [the one SC's came with] is the appropriate upgrade, and the one I have the spare parts on the shelf for!

Hi Warren,
Yea that's what I was thinking , No advantage just cheaper to build.
I'm not going to upgrade or is it downgrade either when mine goes.
It's at about 79K mi now on my SC. I wonder how long they have been known to last, The alternators that is? :cool:

I have had my 1987 Carrera for 3 months. I just noticed a couple days ago that my parking lights were flickering or fluttering. Upon further investigation (duh) my headlights and dashboard lights do the same thing. It is not a radical high/low flicker, it is just a constant little flutter.

I am sure this is not normal. Could this be my VR??? Do I need to change this thing out ASAP? My Carrera is my daily driver. Help!

Mike

The alternator should be able to be rebuilt a couple of times, shouldn't it? At $25 replacing a VR isn't too painful. A new alternator on the other hand...

Just noticed last night... my lights get brighter as I rev the engine and dimmer as I let off. Alternater going south?

Are Alternators w/out the internal VR even available?

I would think that if you don’t want to “upgrade”, then you should start looking for the place that you will want to eventually rebuild yours. They may be available as rebuilt units but I’ve never looked, I thought I’d be stuck w/ the internal VR has my only choice.

I don't know why you couldn't rebuild your old alternator, I've had them done for other stuff by a shop that will rebuild your core, even while you wait so you know what they did.
Those alternators are easy to get at though unlike the 911.
I've gotten a couple hundred thousand miles out of a rebuilt alternator on my diesel truck but it's not spinning a fan.
I'm not sure what fails on our 911 alternators if it's just the need for new brushes or whether the bearings go out or both. I like to overhaul mine though as I know where it's been. The advantage to going new would be time, knowing what your getting and a higher wattage. :)

The 911SC '82 and '83 internal reg. alt. are the WORST Porsche alts.
These units will fail quickly if you use the large type of 911 battery.
You should ALWAYS avoid upgrading to this type of alt. The rating
difference is only 5 amps between this one and the stock '81 alt.

The '82 & '83 928 have basically the same alt. and it fails the same
way. The '84-'89 Carrera alt. is much more reliable, although from
the same French manufacturer, because of better diode heatsinks.
They still have overcharging problems because of the heat effect
on the regulators.

Get those '81 and earlier alts rebuilt!

Have Fun
Loren
'88 3.2

Momo, C U: I think you both have alternators with integrated regulators and, unfortunately, it sounds like you both may be headed for trouble. Put a voltmeter on the battery and rev the engine. The alternator should be putting out around 13.5 volts. Also, the battery should be around 12.5 volts with the engine off. If your readings are within the normal range, then check all of your grounds, as they are know to corrode.

Let us know what you find.

C U L8R (think that's right):) .

That's not unusual. After you start the car with 12 volts supplied by the starter, the alternator must then come online to power the electrical system - to recharge the battery for next start and to have a sustained source of voltage for the system. For this to happen, the alternator contains diodes which must be 'excited' for it to commence output. This is usually a relatively low RPM and may vary with the age and condition of the alternator. Mine needs about 1000 rpm's, but but my old tired one needed more like 2000 rpm's...when the lights brighten, that's your clue it's online. The alternator will actually produce more voltage than is required, that's why the voltage regulator is used...to prevent voltage spikes through regulation and to drop it to 14 V.
Ryan

Thank you scottb!

I checked the battery and it read 12.6v with the car off. With the car at 2,000 rpm, the reading was 14.2v. I had another person observe the lights and he felt they only flutter when the car is at idle. All the flicker goes away at even the slightest increase in rpms. My idle is kind of rough and the flutter seems to be associated with that.

I think I am going to leave things alone for now. I may not have a problem. The flutter or flicker is very, very subtle and it is only at idle.

Mike

Well this is what I found...

I am on my third battery and have check voltage at the battery on the first two, the readings were fine. With my lights brightness verying with engine speed I knew something was wrong, so I did a visual inspection of the battery before pulling the alternator.

The battery was puking fluid, so I knew it was boiling over, therefore my voltage regulator was the culprit (this may have been happening at a higher RPM than the recommended 2000 RPM test range, which is why I missed it on the first two batteries). After cleaning the front of the car and anything stowed (including the battery) with a water and baking soda solution, I decided to pull the alternator, all went well (I think the powdercoat bug has bitten, but that is for a different thread).

While the alternator was still together I checked the bearing play and all seemed well. Then I removed the voltage regulator and brushes. One of the wires going to the regulator had a missing piece of insulation (don't know if that is the cause of the failure or something I did on removal). The brushes and the alternator shaft were worn a bit, but still made good contact. I will order a new voltage regulator today to fix the problem (I have an internal regulator that also houses the brushes).

I then spilt the alternator halves so I could clean and inspect the windings, etc. While I have it apart I will clean the alternator shaft with emory cloth where the brushes make contact. Then blow out dust, shavings, etc. with my air compressor before reassembly.

I don't know if it matters but as I was taking the alternator/ fan/ housing out and during disassembly of the alternator, I made marks so I could line up the pieces in the same orientation on reassembly.

Hope this helps.

Oh, I would suggest you remove and clean the ground from the engine to the alternator, and while your at it clean the ground from the battery to the body and the body to the transmission.

Be very gentle inside that alt. I would recommend a 1/2" paint brush with fine bristles and gentle prodding to loosen up the dirt, etc. Be careful with the air nozzle as it is possible to damage the internals if you blast it.

Also, as far as abrasives go, there are abrasives that won't leave a residual, current tracking trail (iron-based, etc.).

John

Brakleen spray and a cheap 3/4" bristle brush (commonly called an acid brush) works quite well to clean inside alternators and starters ... no high pressure air really needed! Messy job ... lots of old newsprint needed to catch the crud!