schlag

I started my 944NA last night and much to my dismay the voltage meter was reading something super low, in the 11v range.

After a few mins it went back up to 12v and I thought "Hm, Odd."

I (rather stupidly) drive it somewhere today with voltage around 12. As I drive I notice it gradually getting lower, and lower, and lower until its bottomed out at 10v. At that point my car starts running TERRIBLY, rough idle and everything else. I try to start it again, just for giggles, and the thing won't even start (without jumper assistance).

Shut it down. AAA comes and jump starts it. It runs well for a few minutes before it again starts running rather roughly. I turn it off and call the flatbed towtruck.

It looks like it can't hold a charge for more than 5 mins!

Battery is brand new (less than 6 months old) so I doubt that. Alternator belt looks good but I've never replaced the alternator so I've no idea it's condition.

What could be causing this problem? Alternator, regulator stuff, battery...?

Shutemup

your alternator is toast, that's my guess

advance auto carried a lifetime warranty one for mine at a reasonable price

Jakerx

yep it definitely seems like your alternator has gone byebye...have no fear though...it's not very hard to replace yourself...you can have it rebuilt (if you can go without the car for a while) or get a rebuilt one and send in the core...good luck amigo

goingboeing737

There is also a set of brushes that install from the rear of the alternator (at least on my early car).

A lot of times these will wear down to the point of not working at all.

I upgraded mine to the 13.5 - 14.0 (something like that) volt unit.

I did it while the alt was out of the car. It is kind of a PITA while it is still in the car, but can be done.

I think IceShark sells them for about 20.00 to 30.00 (don't quote me) I got mine from a alt /elec shop here for about 20.00.

If you pull the alt and take it to a auto parts place they can usually bench test them for a couple of bucks. While you have it out you can look at the brushes and see what you think....

My .02,,,,,,,, could be anything......

Jakerx

hey james are you talking about the adjustable voltage regulator?

athens944

I just experienced a similar situation with my '83 944 NA. My car slowly died on me after a spirited 4 hr drive on the interstate.

The alternator was not working properly due to the "brushes" on the voltage regulator being worn done considerably.

I replaced the voltage regulator and this seems to have done the trick. It was fairly simple to get to on my '83. I had to remove the airbox and a use a short phillips head screw driver to remove the votage regulator. ( A nice bright flashlight helps to see the screws) It is a little difficult to find bcause most of the voltage regulator sits inside the alternator. I think the Haynes manual has a short section on it.

Anyway, the v. reg are between $20-$62 depending on where you shop. Rebuilt alternators are $60 - $150. Let us know how it turns out!

IceShark

I think he is. I sell the adjustable ones for $21 with the shipping and packing. $16.50 is the base price if you are getting something else like bulbs or cables. Don't pay 40 or 60 bucks for these.

You may also have the rectifier diode package going. That is on the order of 40 or 50 bucks, as I recall. Outside of the labor, I'd try the voltage regulator for a cheap blind fix. I've had guys send me in voltage regulators that had brushes that were 1/8" long. Stock is around 7/16". That difference will do it.

goingboeing737

Yes, if you want to get "technical" about it......

I was lost in the 60's (having just done a search and post on Cherry Bomb Mufflers ) and couldn't remember the exact part name...

BTW... I had an aftermarket belt give me fits on charging as well. Changed to Gates and it charges correctly all of the time.

schlag

Interesting info.

Is there a way to test for exactly which part has failed? Or is it just the ol "replace everything in the area until it works" ?

pete944

Try the regulator that Iceshark sells. It's hard to go wrong for $21.
Mine was running around 12V on the gauge but when I would turn the headlights on it would drop to around 10.5V. I installed his regulator (14.8V) and the gauge stays at 14V now regardless of what accessories are turned on.

Luis de Prat

I'm a happy new IceShark full headlight kit customer, but still a bit hesitant to have a go at replacing the voltage regulator on the alternator in the S2 just yet.

Pete, how tough was it on the 944S2, and did you need to pull it out of the car to replace the regulator?

pete944

Luis, I pulled the alternator out and it's not that hard of a job. I suppose it could be done with the alternator in the car but it would be very, very difficult. Remove the alt. belt, the AFM, and the shroud on the back of the alternator and you can remove it pretty easily. The regulator itself is a 2 minute job.
I kept putting it off thinking it would be a pain but it wasn't at all.

Luis de Prat

I've been away from the S2 for awhile and have been tinkering more with the 83 until now.

Would I need to remove the power steering belt in order to get the alternator belt out? I've replaced the accessory belt on the 83 a lot, but it doesn't have power steering.

Do the alternator belts take a ton of torque? I recently replaced the starter on the 83 and had to use a second floorjack to push the wrench at one point.

What else needs to come out? The whole AFM box?...

Thanks a lot for the help, Pete.

pete944

Ok, the p/s belt has to come off first, then the a/c belt. The AFM box only has a few bolts holding it on and 1 electrical connector, it comes out easily. There are only 1 or 2 bolts holding the alternator on, remove those and then you can move the alternator around enough to take the shroud off the back of it. Disconnect the wires to the alternator and it will come right out. It's a lot easier than it sounds. Ther are 2 screws that attach the regulator. It's very obvious once you have the alternator out.
When you reassemble, tighen the belts until you have about 1/4" or less deflection in the longest span.

Almost forgot, disconnect the battery first!

IceShark

Luis, I haven't worked on an S2 but it can't be any harder than a turbo. So don't be afraid, it just takes some time getting at the alternator.

You may as well replace the alt/AC belt while you are at it. Turn it inside out, flex it and look for cracks on the inner 6 ribs. But for 10 bucks cost I'd just replace it if it hasn't been changed in the last 5 or 7 years. You have a 90 S2, that may be the original belt so time to toss it.

And Pete is right, make sure you disconnect the negative battery cable before you start doing anything. The main power cable to the alternator is always hot, directly off the battery (via the starter) and you can arc weld with that bugger!

BTW, did Spanish Customs open your box and rummage through it? No one seems to bother these packages even though they have all that heavy wiring in the bottom.