Charging/Electrical Problems With A/C On? - Page 2 - PeachParts Mercedes-Benz Forum

Matt L · #16 10-22-2006, 10:58 PM

Quote:

Originally Posted by gmercoleza

What about the electromagnetic clutch on the compressor? That can cause a considerable power drain. I checked to make sure the compressor was engaging, which it was.

I would hardly call it considerable. Look at the size of the wires that feed it. Compared to the cabin fan, it's noise.

mbdoc · #17 10-23-2006, 08:28 AM

Try disconnecting & cleaning the battery ground strap(small nut) beneath the rear seat..most likely not making a good ground there.

gmercoleza · #18 10-24-2006, 08:50 AM

I will check the battery ground strap tonight.

Question: do my voltage readings indicate that the alternator is OK? It would seem that if the voltage can get up to 14.02 then the alternator must be capable of putting out a decent charge. I know voltage is not the whole picture (need to measure amps too) and so I am pulling the alternator tonight to have it bench tested. But am I wasting my time?

gmercoleza · #19 10-24-2006, 05:18 PM

M.B. Doc, you may have hit the nail on the head pointing out the grounding nut. I'm not positive of that yet, but with all the hours I have spent, this is the closest thing to evidence of high resistance that I have found anywhere in the system. See pics of both sides below. Is this enough corrosion to cause the problems I described? The dealers are out of stock - can this be cleaned with a wire brush/drill and contact cleaner? Or should I try a generic cable? A cable is a cable is a cable, right?

FWIW, I pulled the alternator and had it bench tested 3 times, and it passed. I'm getting ready to take the battery for a load test - should I bother?

RAYMOND485 · #20 10-24-2006, 06:08 PM

1984 300d Turbo 140,000
Clean With Wire Brush Or Replace Cable With Same Size Take The Old
One To Any Auto Store And They Will Find One To Use, Maybe $5.00

david s poole · #21 10-24-2006, 06:14 PM

i saw another ground strap looked just like that in a 210 e320.it had been flooded.

gmercoleza · #22 10-24-2006, 06:29 PM

So are we all in agreement that this is the culprit? Meanwhile, I soaked the cable end and the nut in hydrochloric acid for 20 minutes, rinsed, wire brushed, soaked in acid again, rinsed, then filed until shiny. Due to close quarters I am just wire brushing the stud at the chassis as best I can. I will post pics soon.