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walshja · Joined: 03 Apr 2001 Posts: 1139 Location: guilford, ct, usa

My alternator has been making noises recently, grinding noises, and today I got the code 36 - control unit supply check engine code.

I put a meter on the car, and the alternator is charging over 15v, not good.

car runs fine still, is the check engine code due to the over charging alternator? will I ruin anything (besides the battery) if I continue to use the car?

and it looks pretty easy changing the alternator, am I correct? need to removed air duct work and maybe that is it?
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joe

1994 325iC, 195k miles
http://home.comcast.net/~walshja/index.html <--- check it out

walshja · Joined: 03 Apr 2001 Posts: 1139 Location: guilford, ct, usa

well, replacing the alternator is pretty easy !!

got the old out, will get a new one tomorrow

is something ruined on the with the fault code I'm getting? or will it go away with the new alternator?
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joe

1994 325iC, 195k miles
http://home.comcast.net/~walshja/index.html <--- check it out

walshja · Joined: 03 Apr 2001 Posts: 1139 Location: guilford, ct, usa

1 final thing, 205k miles on the original alternator !!!
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joe

1994 325iC, 195k miles
http://home.comcast.net/~walshja/index.html <--- check it out

PJK

Hi Joe,

I think there is a good chance that the out of control alternator is what is giving you the code. Disconnect the multi-pin connector at the back of the alternator, clear the code, then restart the engine. If the code does not return I'd say the electrical system survived the ordeal.

I doubt that 15 Volts will hurt much other than the battery and of course the lamp life will be sharply reduced. The thing to worry about however is that the battery is what is keeping the voltage down to that level. If the impedance of the battery goes high (like if the electrolyte boils away) the voltage can go much higher and fry the DME computer and who knows what else. Untill you get the alternator fixed leave the connector on the alternator disconnected. If the battery gets low reconnect the alternator to top up the battery. Just keep checking the voltage and keep it below 14.5 volts.

Changing the alternator isn't too bad on the e36. Getting it rebuilt by a local rebuilder may be your best deal. I paid something like $65 about three years ago.

Phil

walshja · Joined: 03 Apr 2001 Posts: 1139 Location: guilford, ct, usa

hey Phil

thanks for the reply, you calmed me down, hopefully with the new alternator and clearing of the code everything will be OK.

spent an hour this morning trying to find an alternator, only found 2 in the state of CT, and the dealer was not one of them.

Costs

Dealer - $462, delivered next week
Breaker yard - $50, but couldn't get me it today
CarQuest - $199 brand new Bosch

installing now !!
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joe

1994 325iC, 195k miles
http://home.comcast.net/~walshja/index.html <--- check it out

walshja · Joined: 03 Apr 2001 Posts: 1139 Location: guilford, ct, usa

you were right Phil, new alternator, code is gone !!

pretty easy job !!

thanks for your help
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joe

1994 325iC, 195k miles
http://home.comcast.net/~walshja/index.html <--- check it out

PJK · Posted: Sat Jul 17, 2010 11:58 am Post subject:

Glad to help,

Phil

floridamary4 · Joined: 18 Jul 2010 Posts: 4

thanks for the input Smile

it works out
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Heating Repairs

walshja · Joined: 03 Apr 2001 Posts: 1139 Location: guilford, ct, usa