Bad Alternator?

[Misterchinn]

The battery "L" telltale light started to glow dimly. I'm guessing bad alternator isn't giving the battery a full charge? (I use a trickle charger when garaged, so battery is charged before driving).

If it is the alternator, would this be a good source for a replacement? Anybody use European_Auto_Tech before?

http://cgi.ebay.com/ebaymotors/ws/e...STRK:MEWA:IT&viewitem=&item=260208333239&rd=1

Thanks for any advice.

 

[velocewest]

That is an internal regulator alternator. The original for the e9 is external regulator. If you are going to swap to an internal reg version, get at least a 65a alternator, so you pick up some much needed capacity.

The swap is easy; just take the blue wire from the external regulator and connect it to the D+ connector on the back of the internal reg alt.

You can leave the external regulator in place on the inner fender if you want it for the original look.

 

[HB Chris]

Alternator

I just bought an 80 amp alt from BNR on eBay. I called them up, he knows these cars, he made one up and I had it in 4 or 5 days for $100 plus shipping. It has the internal regulator, I am doing as Tony advises and leaving the old regulator in place but removing the short 3 wire harness between alt and old regulator. If you have Hellas and stereo/amp it is highly recommended.

 

[jmackro]

I just installed a 65a Bosch "one wire" alternator that I got from BNR. It works, but does something odd:

Of course, the indicator light comes on when I turn the key to "on" before I start the engine. Once the engine starts, the light stays on as long as the rpms remain < about 3,500. To get the alternator to begin charging, I need to rev the engine above that level. But, once the light goes out, it stays out, even at idle. Hooking a voltmeter across the battery confirms that it doesn't begin charging until I rev it, and that it keeps charging thereafter.

Does this make any sense? Anyone else have this experience? As long as it isn't a symptom of an improper rebuild, I can live with it. But, this is a "new" unit, and if it is gong to be less reliable than my old one, I want to deal with it.

 

[Bwana]

I just installed a 65a Bosch "one wire" alternator that I got from BNR. It works, but does something odd:

Of course, the indicator light comes on when I turn the key to "on" before I start the engine. Once the engine starts, the light stays on as long as the rpms remain < about 3,500. To get the alternator to begin charging, I need to rev the engine above that level. But, once the light goes out, it stays out, even at idle. Hooking a voltmeter across the battery confirms that it doesn't begin charging until I rev it, and that it keeps charging thereafter.

Does this make any sense? Anyone else have this experience? As long as it isn't a symptom of an improper rebuild, I can live with it. But, this is a "new" unit, and if it is gong to be less reliable than my old one, I want to deal with it.

I think it is partially OK, you have to establish the "field current" to get it to start generating electricity. However, I'm suprised at how high you have to rev it to do so. Should start generating at around 1,500 revs at most.

Second paragraph

http://www.pelicanparts.com/techarticles/914_alternator_troubleshoot/914_alternator_troubleshoot.htm

 

[dang]

I just installed a 65a Bosch "one wire" alternator that I got from BNR. It works, but does something odd:

Of course, the indicator light comes on when I turn the key to "on" before I start the engine. Once the engine starts, the light stays on as long as the rpms remain < about 3,500. To get the alternator to begin charging, I need to rev the engine above that level. But, once the light goes out, it stays out, even at idle. Hooking a voltmeter across the battery confirms that it doesn't begin charging until I rev it, and that it keeps charging thereafter.

Does this make any sense? Anyone else have this experience? As long as it isn't a symptom of an improper rebuild, I can live with it. But, this is a "new" unit, and if it is gong to be less reliable than my old one, I want to deal with it.

I'm assuming it has the same sized pulley on the new alternator?

 

[Arde]

I think it is partially OK, you have to establish the "field current" to get it to start generating electricity. However, I'm suprised at how high you have to rev it to do so. Should start generating at around 1,500 revs at most.

Second paragraph

http://www.pelicanparts.com/techarticles/914_alternator_troubleshoot/914_alternator_troubleshoot.htm

From the write up it sounds like an old bulb path with high resistance or low wattage bulb
could cause that.

Not sure if you can push-start your car with such a setup if the battery is really dead...

 

[jmackro]

I'm assuming it has the same sized pulley on the new alternator?

Good point. Yes, while I didn't compare the pulleys in detail, the existing belt fit with no difficulty, and "eyeballing" the new pulley, it looks about right.

Let me check the indicator bulb wattage. I had an LED bulb in there back when I still had the stock alternator in place - that thing took so little amperage to light that it would never go out. So, I'm pretty sure that I replaced the LED with one of the old OSRAM 2W bulbs. Maybe I should search for a 3 or 4 watt bulb.

 

[steve in reno]

JMACKRO
I replaced my alternator a few years ago with a new style internal and rewire. Mine also takes a little while to show charging on my voltmeter. I don't need to put a lot of rpm, just time for the change to charge, 1-2 minute of run time or so!
I have had no problems with the charge system or battery state so it appears to be good.
It did freak me out initially when there wasn't an immediate charge showing, but hasn't been an issue!
Automobile electrics always gets my panties in a bundle.
steve

 

[jmackro]

I replaced my alternator a few years ago with a new style internal and rewire. Mine also takes a little while to show charging on my voltmeter. I don't need to put a lot of rpm, just time for the change to charge, 1-2 minute of run time or so!
I have had no problems with the charge system or battery state so it appears to be good.
It did freak me out initially when there wasn't an immediate charge showing, but hasn't been an issue!
Automobile electrics always gets my panties in a bundle.

Steve: OK, thanks - the fact that yours is still working years later gives me some confidence. I just wanted to make sure that my new alternator didn't have some defect that would cause it to crap out right after the warranty expired.

Mine will charge immediately if I really rev the engine - it doesn't take as long as a minute.

Not sure if you can push-start your car with such a setup if the battery is really dead...

Ariel: Hmm, good point. Well, that's why I carry jumper cables. I just have to hope that I don't leave the lights on while I'm off-roading my coupe out in the wilderness.