biker349

hi, i have a 2004 cl600 it uses a water cooled 180 amp alternator. the 2000-2002 cl600 uses the same alternator, but it is only rated at 150 amps and is half the cost of the 180 amp alternator. question is will using the 150 amp alternator cause any problem in my 2004 cl600?
thanks for your input

Ausmbtech

Unfortunately the 2 alternators aren't interchangeable. The mounting points are completely different. You'll have to replace it with another water cooled alternator. If you do the job yourself make sure you replace all the coolant seals too.

biker349

than you, but the 150 amp cl600 alternator is also water cooled. i believe that it is exactly the same alternator configuration as the 180 amp alternator. they are both water cooled. am i correct about the configuration?

Ausmbtech

If they are both water cooled then they should be "physically" interchangeable but I'm pretty sure the way the voltage regulator is operated changed as well so they wont be "electrically" interchangeable.

I suggest you stick with the correct 180A alternator.

biker349

thanks for your knowledge and input. i'll have to check into that.

biker349

okay, still researching. i believe the 150 amp has the plug for the alternator with 2 grooves on the bottom and one on the top. my 180 amp is reversed with 1 groove on the bottom and two on the top. i believe the plug will still work by flipping it around, but i don't know if this will reverse the polarity, or cause a malfunction. any ideas? i'm trying to locate a cheap 180 amp voltage regulator part# F00M255203. any help is greatly appreciated. you can find all parts for the 150 amp water cooled alternator. the 180 amp is almost impossible to find and it was produced at least from 2003-2006. go figure.

Ausmbtech

Maybe your best option is to get your alternator rebuilt rather than locate another one. What is the problem with it?

biker349

hi, it doesn't charge. i'm thinking voltage regulator. this is the original alternator and was replaced at 50,000 miles with a used one which is still good. i'm assuming the last owner ran the car with a dead battery which caused the alternator to go bad. he replaced the battery just before i saw the car. don't know why it's so hard to find 180 amp alternators, parts, or rebuilds. the cheapest i've seen rebuilds for is from $600-$1200. new $2100. since i have a good core i want to salvage it and have it ready in case i need it in the future. i already disassembled it and would like to replace parts if i can find them. thanks for your interest and knowledge. it seems that you were correct about the voltage regulator having the minor change i noted earlier, other than that the voltage regulator is exactly the same. what would your guess be as to what component has failed in the alternator that causes it not to charge? i'm getting close to giving up on this project but would appreciate your feedback.
the best

Ausmbtech

Most likely it is a failed regulator, Obviously hard to be certain without testing it. I would suggest pulling the regulator out and searching for the Bosch part number instead of looking for a Mercedes part as most Bosch parts are used in a number of vehicles and you may find what you're looking for that way.
I know last time I worked on a Mercedes water cooled alternator I found most of the parts were also used in the BMW X5's and some V8 Range Rovers.

biker349

thanks again. i've been searching for the voltage regulator for 3 days using the bosche #. found one for $90 on ebay. you are also correct about the bmw alternators. according to the listing there are 3 bmw alternators that are supposed to have the same voltage regulator as the mercedes 180 amp water cooled. you really know your stuff.
the best.
p.s. is there a way i can test the voltage regulator myself while the alternator is off the car? it's brushless.