Alternator/Charging System Question

[GaryK227]

I have a 2002 Boxster with the 2.7 engine and manual trans. and 78,000 miles (about 7000 track miles).

The car has been in the body shop for the last 7 weeks (please don't ask). The other day they called and said the battery wasn't holding a charge. As i had just replaced the battery less than 2 years ago and it has a 30 month full replacement warrenty I picked it up and took it back to where I got it. Long story short, they charged it up and said it was fine. I went back to the body shop and took the car over to the shop where I bought the battery (Porsche specialized shop). I should mention that the Battery/Gen light was coming on intermittently the whole drive over (only a couple of miles). It would come on for a few seconds then go off for a bit of time, then on again, off again. They then measured the voltage across the battery while th ecar was running and it was low (about 11.8) and said I need a new alternator.

Now for my questions -

I have read on this forum that a lot of tims it is just the voltage regulator. Given the mileage on the car, should i just replace the VR or go for the entire alternator?

The shop has sourced a rebuilt alternator for $350. They are quoting $650 for th ewhole job. That would translate to about 3 hrs labor. Does that sound right? (It sounds high to me). Does anyone have access to the "official" time guides for the 986?

Thanks for any help you can offer.

[bmohr]

not terriblly hard to diy with the writeups found here. Plus you could get yours rebuilt for half the price they are quoting. Or even one from Oklahoma Foreign salvage yard for 100 bucks. but yeah, if you are going by official numbers 300 bucks for labor may be a bit high, but not far off.

[Tool Pants]

I would first make sure it is not really the battery. Autozone tried to play a game with me when they said the battery was "ok" and I knew it was bad because I had tested it before I bought it in. They do not like warranty claims. I wanted my battery load tested. I was watching the guy test it and kept asking him if he was doing a load test. His answer was to talk to the manager because he knew the battery was bad and did not want to tell me. My battery had a short and I knew that from my test. I would fully charge the battery with a 10 amp charger and then 12 hours later it was dead. One of the cells was dead which means a short that quickly drains the battery. What they guy was testing was the voltage. And voltage is not what starts the car. It is amps.

The Boxster uses a standard Bosch alternator used on other cars such as VW/Audi, but the mounting is different. Don't remember for sure, but I think it is 55 amps. Check online with parts places suck as Kragen, Pep Bos, and Autozone. It has been 2 years since I looked and I think the prices were about $220. It gets confusing because sometimes they do not come with a pulley, but that is good because it costs less to buy it that way. You can reuse your pulley. You car with a manual transmission will have the freewheel pulley.

I have a rebuilt one I bought a few years ago for some reason. Paid about $100. But it is too heavy to ship.

What usually goes out is the regulator. This is a standard regulator used by Bosch. If you are handy you can take the alternator to a shop and have it tested to see if it is the regulator. Then replace just that part. If you are not handy and there is a shop in your area that rebuilts alternators you might drop it off.

The point is, it is an alternator like any other car has. There is nothing special about the Bosch alternator used on the Boxster. Just like there is nothing special about the battery.

[1schoir]

...

The point is, it is an alternator like any other car has. There is nothing special about the Bosch alternator used on the Boxster. Just like there is nothing special about the battery.

Good to hear some sanity around here that does not buy into what Porsche wants us to believe! :clapping:

Regards, Maurice.

[wvicary]

Remove the alt and have it rebuilt. Be sure to inspect the pulley that it does free-wheel and is not seized or slipping if yours is of that type.

[Glyn]

Alternator is 80Amps I think.

[pk2]

I'd agee with tool pants, Take it to an autozone type place. I'm going to guess somthing is grounded to some degree and is drawing on your battery. Sinse it happend during or after an accident, I would guess the prob. is result of somthing being bopped into somthing else electrical or, the shop put it back together wrong. Other wise, quite a coincidence.

The good folks at Autozone will be able to tell but, an easy test is; if you turn everything in the car off and disconnect the pos. on you battery, tap the lead on the terminal, there thould be no more than little crackly sparks. If the battery is loaded up (somthing awry, like a ground) you'll get a pretty hardy spark.

Regards, PK

Edited December 4, 2009 by pk2

[GaryK227]

Thanks to all.

In reply to pk2 and tool pants - the battery was recharged and then sat overnight. Still put out 12.8 volts. In the car, with the engine running, the voltage across the battery was only 11.8 - not enough to keep it charged. Damage in the accident was to the front bumber annd the left fender and door - nothing further back.

I can certainly take it to AutoZone or Advance (both are nearby). At this point I am inclined to look a little further - make sure all the connections are tight, use my multi meter at the alt. I have to find a shop in north jersey who can check out the alt if I bring it to them.

Of course I would appreciate any other thoughts, suggestions, or recommendations as to shops in norht jersey that specialize in alternators.

Gary

[Tool Pants]

Here is the back of the extra alternator I have. Looks like 120 amps. The thing with the orange printing is the regulator. It is an external regulator and designed so that you can replace it without taking the alternator apart. Output voltage is 14 volts.

Interesting to see the 964 part number.

[wvicary]

Just a general warning, don't remove a battery cable and tap it against the battery post to watch for sparks. Batteries produce hydrogen gas and a sprark could ignite it. Test the system correctly and safely or not at all.