newer alternator for 66 200D - PeachParts Mercedes-Benz Forum

ZLandrum · #1 07-19-2011, 03:30 PM

Hey guys, I was talking to my cousin about how my alternator in my 66 200D has issues keeping the battery charged, is there a way that I can put a new or newer alternator in there instead of the one that's in use now? Like, can I bypass it with a generic alternator, or is there a setup already for an updated alternator? Thanks!

Zach

Chas H · #2 07-19-2011, 07:11 PM

Take your car to an electrical rebuilding shop and have the alternator tested. This can be done with the alternator in the car. If they find a problem, have them rebuild the alternator.

wbain5280 · #3 07-19-2011, 11:20 PM

Get a modern BOSCH internally regulated alt from the junkyard. 80 amp from a late 80's W126 would work.

mercmad6.3 · #4 07-20-2011, 12:54 AM

A 200D hardly needs it's alternator so it sounds like yours is probably in need of work . Warrens suggestion of a later one is good because it bolts straight in and you only need to alter the wires (Big red one to battery,blue one is for dash light ) .But i couldn't think why a 200D would need a 80 amper unless your battery is actually too small. The correct size needs to be around 88amp /hour

Are you running a big sound system ?

ZLandrum · #5 07-20-2011, 12:52 PM

thanks for the responses... mercmad, I actually was wanting to put in a sound system (not huge, or obnoxious, but something that I can listen to music with) and I was also wanting to run fog lights on the front. but the main reason I'm wanting to upgrade is because it doesn't keep the battery charged... and it's left me stranded with a dead battery several times. I think the belt actually isn't working like it should, but before i messed with that I was wanting to know if the alternator would keep the battery charged for the other stuff I'm wanting to run (said stereo, said fog lights)

mercmad6.3 · #6 07-20-2011, 08:33 PM

Have you got a multimeter? with the engine at idle you should have 13.7 volts minimum across the battery . If not,the alternator is sick. With the engine off,you should still have 13.7 volts. if not,the battery is dead. 12 volts isn't enough to start a diesel once you have glowed it and started cranking.
A visit to a wrecker should get you any large alternator from a later Mercedes up to 1992 which will fit right in.
Regarding the belt, it should be tight but on the longest span,you MUST be able to push it down 3/4" . if it's too tight you can damage the alternator and engine bearings and a new belt is always a good idea. Notice that the alternator has a 17 mm bolt and nut. loosen the nut,and you turn the bolt to adjust the tension. it has a little geared rack on the mount bracket.