Alternator, anybody? - PeachParts Mercedes-Benz Forum

elau · #1 05-12-2007, 05:17 PM

Before I order an alternator from Phil, I want to see if that is what you all think. Car won't start, and the battery is new. Purchased in January. Road Side came to the house and started it right up. Drove it for couple hours. As soon as I pull into garage, car won't start again.

I think the alternator craped out. What do you all think? Or something more serious than that? Am getting a little tired of this constant no start issue. Any advise is greatly appreciated.

450slcguy · #2 05-12-2007, 09:36 PM

Try putting a volt meter on the battery terminals. If it reads 13/14+ volts, the alternator is charging. If 12 or less, then you got your answer. Also check your cables for corrosion or poor contact.

sublettd · #3 05-12-2007, 10:23 PM

Stop in at AutoZone and they will check it out for you at no charge.

elau · #4 05-13-2007, 12:17 AM

Quote:

Originally Posted by user name

does the warning light come on , or does your car have a gauge to tell if it's charging ?

No. It is a '95 R129. Wish they have a volt meter in the dash like in the old days.

elau · #5 05-13-2007, 12:18 AM

Quote:

Originally Posted by 450slcguy

Try putting a volt meter on the battery terminals. If it reads 13/14+ volts, the alternator is charging. If 12 or less, then you got your answer. Also check your cables for corrosion or poor contact.

Cable is good. Have not checked the voltage yet, as I don't have a volt meter.

elau · #6 05-13-2007, 12:19 AM

Quote:

Originally Posted by sublettd

Stop in at AutoZone and they will check it out for you at no charge.

Only if I can get the car started

450slcguy · #7 05-13-2007, 10:45 AM

You don't have jumper cables?

tecqboy · #8 05-13-2007, 05:45 PM

It is also possible that the voltage regulator or brushes have failed. I'm not certain about your model, but in some these parts ( which are part of the alternator ) are replaceable seperately at a much lower cost than an entire new or rebuilt alternator.

elau · #9 05-13-2007, 09:52 PM

Any suggestion on how to check which part failed? A rebuilt atlernator is closed to $300. Would like to avoid senting that much if I can identify what part to replace.

SunGuy · #10 05-14-2007, 12:53 AM

The voltage regulator for your 129 is

http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1UM18K7FN23301PV1Q&year=1995&make=MB&model=SL-500-001&category=F&part=Voltage+Regulator

from Phil if you need it. This is a DIY changeout at approx $33.

If you don't have a voltmeter, when you get the car started again, get it to Autozone or equivalant for them to check alternator output.

Bob