ontario

The voltage in my '88 911 3.2 is occasionally spiking to 18 volts. I suspect it's the alternator or voltage regulator. Is there an external v.r. in this car?

Anyone know where I can get a cheap alternator in Canada? Spring weather has hit and I hate for my car to sit in the garage while I wait for an alternator from the U.S.

Peter Zimmermann

The voltage regulator for your car is attached to the alternator's hip. It's usually recommended that, when a new regulator is fitted, that the alternator is rebuilt by a quality shop. I respectfully recommend, for the well-being of your CD player, tachometer, and other electrical goodies, that you do not drive the car again until the problem is fixed!

Paul K

+1 for what Pete said. FWIW, swapping out the alternator is a major PITA. But necessary, from the sound of it!

Good luck with it!

Paul

'89 Carrera Targa

ontario

Pelican Parts says it's a 3 out of 10 in terms of difficulty. Accessibility doesn't seem to be a problem. What's the difficult part? Separating the fan housing?

ontario

I'm going to pull the alternator today. I'm wondering if there is anything I should do while I have the fan and alternator out. I have about 126,000kms on the engine.

Paul K

Do a search here and on the Pelican board- you'll see what I'm talking about. The only thing I'd do 'while I'm in there' is install a new fan belt.

Hope it goes well!

3.2SLANTNOSE

Make sure that you keep track of the shims when you re-install and go to tension the new belt. If your belt has only been used just a short time, you could probably use it, but if it has some age on it, replace it when you do the alternator swap. Good luck!! Tony.

Peter Zimmermann

...and before you start make sure that you disconnect the battery ground strap!

ron mcatee

When you get the alternator loose and start to pull it out, be careful because there is a ground wire attached to a 13mm case stud nut behind it ( or there is on my 88 Carrera). Make sure all the wires are loose from the alternotr and don't tug on anything as it should all come out easily. I would allso check that ground wire to make sure the connectors are good and soldered, not crimped. I found mine was only crimped and had, over time, frayed some of the wire strands. There was only one strand still connected when I removed it. I made a new wire (a couple of inches longer) with new soldered ends on it and reinstalled it prior to installing the alternator. Works like a charm now.

ontario

I just pulled it. Took me 2 hours. I forgot to mention that my car is a cabriolet which meant I had that little strut at the back of the engine bay to make things more complicated. A lot of cajoling and grunting but I got it out. I only snapped one of the rivets on the airflow housing and bent another one. Repairable. How you get the alternator out without damaging the housing is beyond me.

Oh, and I like the one hidden nut that is at the bottom of the housing. Love that German sense of humour.

Peter Zimmermann

I use two lengths of 4 x 6 wood separated far enough so that the outboard edges of the housing contact a few inches of wood on each side. A gentle drop, or a few, are normally enough to loosen the alt from the housing, then flip it over, set the fan blades on the wood (as much support as you can manage for the blades!) and use a soft mallet to tap the center shaft of the alt (lightly grease the shaft before you put the fan back on). Don't worry about the rivets, many times they're broken.

gerrygug

+1 on the Shims

wwest

This all depends on just what is your definition of "spiking". I automatically assume you don't mean brief voltage spikes that you would need an oscilloscope to see.

Are you saying the type of spiking, brief, just a few seconds, that might be visible on an analog meter?? Or THE analog meter..??

As a general rule the battery, a GOOD battery, WILL NOT allow spiking of the alternator output voltage to the level you state. Provided, that is, that the plus and minus posts of the battery are WELL connected, respectively, to the output and ground/body connections from the alternator.

I would first remove both battery post connections, clean and burnish the posts and connectors, "interfacing", surface connections. Then check that the battery minus is WELL grounded to the body as is the alternator negative side.

I would also be suspicous of the meter itself.

Peter Zimmermann

Little trick for you guys; when you put on a new belt (made by Goodyear, sold by Porsche) put 5 shims between the pulley halves, and the 6th one under the clamping washer. This will get you on the road with a correct tension adjustment in most cases...

ontario

I have an Optima Red that is two years old at the most. I keep it charged with a trickle charger at all times. So I believe the battery is good.

I also know that my voltage spikes are real (last about 10 seconds before settling back to normal) because my amplifier cuts out. The amp has over-voltage protection. This is how I first suspected a problem.

I have also had problems with a fluctuating idle.

Either way, I believe at 129,000kms, it's good preventative maintenance to pull and rebuild the alternator so it's time and money well spent. I will check the battery posts and connections as you suggest before I start everything up.

Thanks everyone. I am off to the rebuilder tomorrow. I did not get the housing off but I am hoping the alternator shop has a puller. I'm a little nervous about using the drop technique.