I suspect my alternator might be on the way out.

On the drive home I noticed the battery voltage on the dash was less than 12V, so when I got home I double checked with my digital voltmeter and yep it was low.

I turned on the headlights to see what would happen but they struggled to ignite and the battery voltage stayed <12V.

Revving the engine had no effect on battery terminal voltage.

No warning lights on the dashboard.

I replaced the battery a few months back as the OEM gave out.

Questions:
Are there any codes I could pull to determine the alternator charging current or lack thereof ?

How difficult is an alternator DIY ? Edit - found smistry007 DIY excellent DIY guide and it seems easy enough.

Looks like I might be getting my hands dirty again after just replacing the spark plugs and coils :-)

One last observation - I did notice that after a restart for a few seconds the battery voltage went up to just under 14V then settled back down to under 12V. Not sure if this tells me the alternator started to charge then gave out.

Might have the battery tested at where I bought it from just in case it's failed - unlikely.

Thanks again guys, Tim

 

That sucks! I had to replace my alternator not too long ago. Not sure if there are any codes that will be thrown. Mine was overcharging - so the regulator went I guess.

It is not that hard of a DIY. I think the hardest thing was reattaching the vacuum lines on the intake. It is just a little tight in that area. I think there are some DIY's on here or some other forums like renntech.

Took me and another fellow about an hour to change it out.

 

Yeah - found the DIY, doesn't look too hard and I like working on my car for stuff like this :-)
Just got to locate either a new alternator or re-build kit, hopefully locally. Either that or order one from Pelican Parts.

No big deal either way as I have a few other cars to keep me mobile !

 

I just had my alternator start over charging, the new alternator from Porsche was around 1100-1200 so I looked around and found re-built alternators for 350-450. I was sure the the voltage regulator was bad, charging 18 volts. My car has 25k on it and it should not need bearings.
I looked around on the internet and made lots of phone calls, everyone
was saying regulators are not available for these cars. I could not find the bosch factory regulator. I found out that the rebuilt ones used an aftermarket regulator. I bought one from a local shop for 40.00 installed it on the alternator in 5 minutes checked it on the shops tester done. The part is made by Transpo #IB225 VR BO it simply bolts to the back of the alternator.

The only problem I had was removing the alternator. The long bolt on the right side pulls a sleeve out locking the alternator in place after you remove both bolts. I used a pry bar and went between the motor and alternator, pry alternator to the left and it will come out. Re-installing will be much easier if you press the sleeve in before re-installing. good luck, Greg

 

Hi Greg,

thanks for the tips and part # - I've tried calling a few of the local shops to get just the regulator but no luck.

Changing just the regulator would be a bit of a gamble as the rest of the connections to the rectifier pack and windings etc look corroded.

Even though the alternator has only done about 20,000 miles I'm going to change the whole item and have ordered one from Pelican at about x10 the price of just the regulator

The removal process of the alternator wasn't too hard, but the bolts holding it in place and pulley in front of it were very tight. Like you I had to pry it slightly.

Just trying to find out what the correct torque is for the bolts involved and if I should change the pulley when putting everything back together.

Tim

 

the pulley on these units have a free wheel one way. The new one should come complete. (thats for the 6 speeed cars) I am not sure of the torque specs.

 

Hi Greg,

the pulley I was referring to is the one in front of the alternator but not attached to it :-)

Sorry if I didn't make that clear.

 

Considered having a shop rewind it? Talk to a stereo store about who does their stuff. If you can have it rewound to a higher amperage I'd consider it. I did this on my Supra and the added amps was good with the stereo, wipers, headlights, pumps, and all the others things. You want full voltage to the fuel pump always Price wasn't bad and it was done by a guy that all of the stereo sites trusted...

 

Not really interested in re-winding it for greater amperage, not even sure I could find someone locally I'd still be looking for a new regulator / rectifier pack - stock is good enough for my needs :-)

Turns out I found another source for the alternator this time on Bay 'California Alternator and Starter" - they had a good deal and excellent feedback so I ordered from them instead of Pelican.

Always amazed at how 'packed in' stuff is within the engine compartment. What would take 30 mins on a regular engine takes about 2 hours on the Turbo :-)