Charge voltage
 

Hello.

I have some problems with the chargesystem on 1990 230CE. I just replaced the alternator with regulator. I don't know if the problem was the same before the old alternator took of the heavens above, but I can only get it to charge at 13,5V, and if I turn on everything, heater, light etc. it drops to just above 12V Does anyone know if this is normal?

I would check your battery connections and make sure they are clean and tight. If they are I would check your ground connection to the body to make sure that is clean and tight. With those accessories on the system should not load down that much...Was the alternator new or used....

This might be expected at engine idle rpm.

What is your charging voltage at 2.000 rpm?

It doesn't make much of a differance what rpm the engine is running at, meybe 0,2 v but thats it. I did check the connections to the battery abd to ground, but they seems ok. The alternator is brand new. I'm realy stuck here. I wonder if it could be the light control unit that is faulty?

What shape is the main alternator lead in? Loose/dirty/bad connection there can lead to a voltage drop and potentially help kill an alternator.

They look ok, but I will check them again. Thank you :-)

Check out this thread:

http://www.peachparts.com/shopforum/tech-help/108691-dead-battery-new-battery-new-alternator-still-dont-like-voltage-post754140.html#post754140

He had "bad" cables. Likely where the terminals are crimped on the ends of the cable. I have seen corrosion at these points before.

And also http://www.peachparts.com/shopforum/tech-help/115014-more-battery-alternator-troubles-2.html?highlight=troubles post #5. There is a good explanation of what voltages should look like.

Mike

Hey Mike, thank you :)