My First MG
 

Mercedes Glitch that is. We went into town Monday and the 300 td wagon was running fine until our last stop. Went in and made our purchases, loaded up, turned the key and nothing. The battery was dead, no warning of any kind, it had started fine up until that very moment. Some kind soul took pity on us and jumped started it for us. I pulled the battery as soon as I got home and took it to Auto Zone for a free check. Their tester said the battery was shot, $75.00 for a new one, gulped and coughed up the $75.00. Went to town again today, had a lot to do, stopped several places and went in to eat lunch. Come out and the same story, dead battery, again we were fodrtunate enough that someone jumped started it. On the way home the ac, and fan didn't work at all, and the tach seemed to work at only 1/2 speed. I assume the generator isn't working and neither is the idiot light, I can't believe those German engineers didn't put an ammeter on these cars. I have an old ammeter here but I don't remember how to hook one up. Can someone tell me how to wire one up to check the gen., or suggest some other troubleshooting idea? If it's not a bad generator any other suggestions/ ideas would be appreciated.

Thanks

Check to see if the alt is putting out some amperage, doesn't sound like it is to me. The idiot light could be out...

More often than not, you only need a new volt regulator.

Buy a new voltage regulator.

I had the same thing, driving late Christmas Eve in a blizzard in my 4matic wagon, ABS and SRS lights came on, lights getting dim, ...

Pulled into a fire station, removed the voltage regulator, stretched the wire holding the brushes just a little so that the brushes would touch, jumped it to start and she charged fine until I got home to order a new VR.

When the brushes lose contact the ALT light will not come on, but it will stop charging.

You can have your old VR re-brushed, keep it as a spare, they're fairly cheap.

- Jeff Miller
190DT

A lesson I learned the hard way..........
 

Before you start chasing after parts, check the batt.-chassis and chassis-engine grounds.

A voltmeter reading across the battery (before-during-after start) will tell us much more.;)