PeachParts Mercedes-Benz Forum - View Single Post

muleears · #1 12-22-2009, 06:49 AM

Had a no start situation after filling up at the fuel station the other day. That morn. I started the car (the 87 124) and drove 3 mi. to the fuel station. Left the lights on while I dispensed 10 gal. of D2. Climbed back in and no start, battery too low. After a jump, I drove to Advance Auto to buy a battery, but had them check the charging system first. They told me the batt. was OK, alternator not charging properly, "low voltage" and "battery needs charging" was the diagnosis. Without lights and accessories on the car seems OK. Took the car home and installed a voltage reg. I had on the parts shelf for just such an occasion. There was no noticable change in voltage across the batt. terminals (car running) after the reg. was installed. My cheap analog multimeter still showed around 12 volts, same as before the reg. install. I then drove the car 6 miles with everything on (lights, accessories) to test. Afterwards I turned the car off and left the lights on high beam for 5 min. I then attempted to start and the battery didn't have the juice to do it.

Did I not drive it far enough? I now realize I probably should have left the electric stuff off so the batt. could charge. Do the brushes on the VR need to be broken in before they operate at full capacity? Where do I go from here? I have the batt. on a 2 amp. charger and it will have been on about 21 hrs. before I get home from work to try again.