92 300E 2.6 with 93k charging system problems
 

Hi all,

Everyone was very helful the last time my faithful car gave me trouble and now I have a new problem.

The car is a 1992 300E with the 2.6 engine. The car has roughly 93k miles on it. Like an idiot I parked the car in the garage a few weeks back and left the dome light on. I recharged the battery and started driving the car and thought nothing of it. Then as I drove over the period of one week the car slowly started cranking slower and ultimately would not start. I assumed that a new battery might be a decent idea and put one in. This morning on the way to work I slowly started to notice warning lights coming on the dash. Abs followed by SRS etc. I turned around and limped the car to within a block of my home. Jumped the car and drove it to my driveway.

I have read some of the posts and have a pretty good idea of what the steps would be moving forward. If anyone had a simple checklist of advice to proceed on testing that would be great. Please dont get too technical as I understand the basics of electrical systems but am not an expert. I am going to throw the car on a lift this afternoon and check grounds, wiring to and from the alternator.

Any ideas would be greatly appreciated. Thanks.

Hi All,

I pulled the voltage regulator out of the car and the rear brush was almost completely gone. Replaced the regulator today and I am crossing my fingers that I am good to go.

Excellent
 

'Chances are about 105% that's your problem.

1.'With a fully charged Battery ("On the Charger" @ 2 Amps overnight , with proper electrolyte levels) check the Voltage at the Battery Terminals [Engine Off].What's the reading?
2.Start the engine and with the engine idling take the Same Voltage reading.
What's the reading.

#1 should be 12.6 to 12.90 Volts.
#2 should be 13.9 to 14.2 Volts.

Yep, with a missing brush it won't work. Your problem is very likely solved. I carry a spare voltage regulator in the glove box just for that reason....I've had one go out on my 300SD....thankfully those can keep going fine with no power. :D

300E 2.6 one problem to the next
 

Hi again all. So I Changed the voltage regulator in my car about a month and a half ago and everything is great with the charging system.

Now unfortunately after 200 miles since when the car is left at idle in gear it starts to buck and sputter but has yet to completely stall. It also has a hesitation off idle when sitting with the rough idle for a bit.

The OVP relay was replaced about a year ago and cured a bad idle stall / hesitation pulling away from a stop.

It seems the new regulator has brought back an old symptom.

Any suggestions??

Start by checking ALL of the vacuum connections, especially the little rubber Ys and fittings.