billthe3

Just incase anybody else feels like testing alternators to see if they fit, I noticed yesterday that the alternator on the oldsmobile version of the mid 90s caprice seems to have the same mounting tabs. I doubt it is an LT1, but it looks like its the common gm efi v8 from the mid 90s.

I can go take a ruler out and messure the distance between the mounting tabs later to see if it is the same distance as the OEM one, if anyone cares to measure that.

eniac

The alternator is on and working great....a little to great. I connected both plugs on the back to the switched power (small stock wire) just to make sure the alternator would be on when started. My voltage was quite high and the warning light(the red one on the stock voltmeter) was on. I then disconnected one if the 2 small wires in the back which made the warning light go off but my voltage is reading at 15.3v. I am thinking the voltage regulator is switched on but not regulating voltage...or would my voltage my voltage be alot higher if that was the case?

Pauerman

The small blue wire from your factory harness is the field wire. It senses the electrical load on your system and adjusts or dictates the voltage regulator's output.

Have you tried just the blue wire on either terminal independantly to see if the voltage output goes down?

eniac

Thats what I thought the blue wire should be but on one terminal it does nothing(alt output at 15v+ and on other terminal the warning light comes on and it's still at 15v+. With it completely disconnected it's at 15v+ but no warning lamp.

I think I have it figured out now though. It appears one of the terminals require constant power. I connected the small blue wire to the terminal that made the warning light turn on. I then connect the other terminal to the main battery wire. Instantly my voltage dropped to 13.8v and the light turned off. Just to be sure I turned on the radio, amps, blower motor, high beams, etc and it still read a steady 13.8v at idle.

I'll have more pics in a few minutes...

eniac

It's finished! This isn't a job that should have taken a week but I was really busy with little time to spend on it. Although it's more work the replacing a stock alt, overall this was quite easy to install. The only items I had to buy were a 1" smaller belt(6PK0965) and the alternator. No extra brackets or bolts. Everything else was reused as was my original intention. I did end up using the smaller Bosch pulley. How I got that to fit is noted above. I am sure there are better options such as an early 944 alt(unclear why that why not widely known in previous threads on this topic) or possibly the other alts mentioned here. I am, however, 100% satisfied with how this one turned out.

These first two pics are with everything installed in running/driving form. Quite a change from the old pic I posted at the beggining of this thread. Tomorrow will be the big test as I am getting up at 9am to drive the car on a 400 mile road trip....wish me luck. lol







So far the only bad thing I noticed is the main power wire in a terrible spot. It still fit great and freed up tons of room but not as much as it could have if that power terminal was moved to...well somewhere else. It doesnt stick out quite as far as it appears in these next two pics. I made a nifty rubber cover to protect the wire and terminal from anything that could possibly ground against it.

billthe3

Good stuff!

SoloRacer

On a friends race car we found out that they used a Suzuki Swift alternator. The previous owner had the mounting bracket milled down to accept the smaller Swift alternator. Looks like you found a better solution since less modification is needed. Besides size I can think of two other good reasons for doing this mod. One is that the alternator is signifigantly cheaper than any Porsche one (I believe a 951 alternator will run $500+) and you can get this alternator pretty much anywhere at any time. When the alternator went on my friends race car and we didn't know what he had we searched all over the city for a 944 alternator (on a Saturday) and were told that it would be a week before we could get one. Not something you want to hear when you have a big race coming up in 4 hours. I can't wait to hear your driving impressions.

Acetylene

Yes, please post results when you have a chance. Hopefully you will have a chance to see how it does at higher RPM. If there is an alignment issue it will show itself in the upper ranges. I am you have a safe and fun trip.

eniac

The alternator worked perfectly even after it got a bath in hot coolant when my upper radiator hose sprung a leak. The leak was my own fault as I forgot that on my car the metal coolant pipe has to be held up while the 10mm bolt is tightened so it doesn't hit the fan. I tightened the bolt but didn't position the pipe up. Luckily I was able to make it to a CarQuest store. They didn't have the correct replacement hose but amazingly I was able to find another hose with the exact size ends(the hose expands at the radiator) and the proper bends. I just had to cut a bit extra hose off and I was on my way again.

eniac

Ironically the local S-G import store here in Farmington Hills, MI did have the Porsche alternator in stock(reman'd unit) for only about $220 so it was readily availible here. I just couldn't justify spending $200+ and still not solving a major issue. Also I doubted that even a new factory alt would last very long due to how much of the heat shield I had previously cut away.

Bri Bro

This is a great post. Lots of good information going on.

I looked up the P/N for the 944 alternators and here is what I found.

1983-85.5 P/N 944 603 108
1985.5-88 P/N 928 603 011

It would be interesting to see a picture of the 944 altenator compared to the 928 unit.

eniac

I don't have pics of them side by side but you can get an idea as the 83-85.5 alts have a smaller housing so the screws holding it together stick out from the housing rather then being inside the diameter of the housing on 85.5-88 alts. The reason I prefer this Nissan alt is that the early 944 alternators still have a solid housing and need the cooling shroud or they will overheat. As mention earlier, I believe the Nissan alt will do a much better job at keeping itself cool by disappating the extra heat. Look them up at Pelican parts. They should have pics of each 944 alt shown.

gt37vgt

hey what kind of nissan engine was it on all the car names are different over here?

eniac

Hmm not sure exactly. It was from a 1997 Quest minivan which would have been assembled by Ford during those years, my guess it would have had the 3 Liter VG30E-V6 engine.

eniac

I recieved a few pm's on this so I figured I'd post what I did with the wiring in case anyone wants to know and to address a couple other questions I have been asked.

This is the only configuration that would give me controlled charging and allow the factory voltmeter and warning lamp to work as intended. It's actually quite simple as shown here:


I had planned on moving that jumper wire from a direct connection to switched power but so far I really see no reason I would need to. Everything has been working wonderfully.

Tool's needed:

$29 angle grinder
$19 drill
A couple large drill bits (13mm-14mm or so)
Normal hand tools for removing alt (13mm, 17mm wrenches/sockets)
Wire crimpers and some heat shrink or electric tape
2 spade female electrical connectors
1 eyelet electrical connector
Alternator belt 1" shorter if using the factory pulley
Hammer (you always need one of these)
A girlfriend willing to ensure there's a tasty Guinness always within arms reach

Your results may differ as I have modified many other items on my car that may have made it easier to remove my alternator mount and various other thing. I suppose you could grind the mount down while on the car although I would highly suggest against it. Way too much room for error if something slips.

Also I did grind the alternator tab down some at first but quickly realized this would not be enough clearance. You may have to grind more or less of your mount to get it to fit. I was worried about weakening the mount by cutting into it, however after close examination I came to see this was another over-engineering feat by Porsche. Once bolted in, the alternator itself will act as support to prevent the mount from collapsing.

The alternator brand I choose is a Beck/Arnley p/n#186-0658 (it's actually a Mistubishi design, no wonder it fits so well! ). As stated other brands may have slight differences which may require more or less work arounds.