Still having problems....starting to get desperate
Symptoms: Car won't start up (slow engine turn over) after several weeks of stop and go city driving. Starter will turn over very slowly, lights dim etc. and voltage will drop to 8-9 volts when this happens. Car driven primarily in the city (HOT 90-100F) & R-134 Retrofit AC on continuosly full blast (california weather)
So far tried:
1) Two alternators (one MBZ and bosch rebuilt from fastlane)
2) Two batteries (both Sears Diehard)
3) Tried voltage regulator and removal of the capacitor (see above).
Still no avail.
-Highest charging voltage at full throttle is 13.5
-Idle voltage is 12.5 usually dropping to 12.0 at idle with AC full blast.
-Startup voltage is 11 volts (rising to 12-12.5 volts at idle with AC. The startup voltage will rise to 12-12.5 after approx 3 minutes as I think the glow plug relay (newly replaced bosch from fastlane) stays on until that time and then cuts out--- a warmup feature I think)
Here's the strange part: I have another identical 300SD that does mainly highway comuting 30 miles each way and its voltage as this problem cars above (if not worse) and it runs fine.
Could this be:
A) Bad alt wiring harness? Haven't tried changing alternator harness (original)
B) COuld the alternator light in the dash have something to do with this. I swapped this with the other car in a desperate attempt to try something. The bulb IS working.
C) Could a bad starter motor do something like this....its a 3-4 year old bosch rebuilt and I don't really feel like replacing it. The starter normally works fine so I doubt it.
D) Any suggestions before I give in and take it to MBZ dealer?
