Alternator interchangeability
 

2005 c230. Alternator took a dump, voltage at idle with no accessories was 12.7 volts and 11.9 with accessories. Installed a remanufactured valeo unit from advance. It worked well for 2 days and then the battery/alternator light came on again. It appears to have adequate output at idle with no load, but under load, it's putting out 12 volts only. I have located a new Bosch unit for cheaper than the valeo. Can anyone confirm if these units are interchangeable? I cannot find any definite answers on this

If the Bosch unit is listed as a replacement for your vehicle it should work.

I notice more and more people having bad luck with remanufactured alternators these days. Even if you buy from the dealer, it will still be remanufactured. I replaced the alternator on my wife Odyssey about a year ago and when she was out of town last month it took a dump on her. She went to the dealer and they said the internals just started coming apart. I bought the replacement unit from O'Reilly Auto with a lifetime warranty. They were good enough to take a replacement unit to the dealer for me but I still had to pay the exorbitant dealer charges to replace.

Please let us know how the Bosch unit works out if you go that way.

Edit: I see the Bosch is the OEM alternator and comes with the Bosch Ultimate Protection Plan Exclusive 24 Month Towing - 1-year replacement warranty, 2-year roadside assistance from Autohaus AZ for $250. The Bosch unit is available from O'Reilly Auto with a lifetime warranty for $182.

99% of the time when your alternator stops charging it's just the voltage regulator that failed, not the whole alternator. The VR is a $45 part that can be replace in 5 minutes once the alternator is removed from the car. And yes, Valeo and Bosch alternators are interchangeable on these cars.

Thanks, I will try to diagnose and switch out the VR from one car to the other and see if this cures the problem of my battery light message coming on in the mornings.

tjts1 - do you have a link to the correct VR for our vehicles?

Here's a link to the Valeo voltage regulator:

http://www.autohausaz.com/pn/VL-0031544006

Does anyone have a part # or link to the Bosch part?

I installed one of these on my 02.
http://www.ebay.com/itm/Mercedes-Vol...72.m2749.l2649

This doesn't exactly match the PN that came out of my car but thats because part of the PN printed on the VR has to do with the lot number. Anyway, this one works perfectly on my 02 Bosch alternator. The PN that came off my car was F00M 145 225. On the bosch alternators, All the RWD C230, C240 C320s had 120a alternators. All the 4matics and C55s had 150a alternators. The 150a and 120a VRs and alternators are interchangeable. A bosch VR will only fit a Bosch alternator and a Valeo VR will only fit a Valeo alternator. But you can put a Valeo alternator into a car that originally came with a Bosch alternator and vice versa.

Thanks tjts1. I need to find what I have on my car so I can get the correct VR if I go that way.

Ok. So I need a little help. Picked up a brand new Bosch alternator. I put it in the same way the old one came out. However, when I tighten it down, the alternator housing is hitting the side of the engine block. If I rotate it 180*, it no longer hits, but now the wiring will not reach. Can someone take a picture or look at the back of the alternator in their c230 and tell me if the black plastic plug is on the top or bottom and if the large positive cable is at the top or bottom?

Thanks.

Just compare it to your old alternator. t's probably setup for the v6. You might have to reclock the housing.

Did it come with a clutch pulley (OAP)? If not you'll have to install one otherwise your belt drive will get torn up quickly.

not sure about that because the alternator housing is slightly different between the two alternators. If someone could take a look at their c230 alternator and report the position of the connections.....

Take some pics.

Ok. I got it figured out. The Bosch does fit. I had some work done a couple years ago in which the alternator was removed. The shop reinstalled the alternator incorrectly which is why the Bosch was hitting. I have some questions regarding the wiring. Can someone take a picture of the routing of the sensor wire and the large positive cable that attaches to the alternator? Thanks.

anyone?

I'll take some pics for you in the am, but IIRC the sensor wire clips to the heat shield behind the PS reservoir, then is routed down between the engine block and the PS reservoir to the alternator. The main cable is not very long so its routing shouldn't be difficult to figure out, as long as it doesn't get to rub on any bare metal..

thank you so much. Those pictures will help me tremendously.

Here are some pics...

thanks for the pictures. They were a big help. Got everything back together today.