300E bad alternator?
 

My car is a 1990 2.6L 300E with approximately 140K miles on it. This morning while driving to work, the radio died (the sound faded out but the display was still working), at the same time the abs and srs lights came on, I also noticed that my blinkers didn't work either. The car continued to run and I managed to get to work ok. I pulled into a parking spot and with the car idling, I turned on the headlights to see if they would still work. At that point, the car died. I tried to crank it back up and I just get a clicking noise. The lights on the dash light up when I turn the key to start it but the car won't crank, it just clicks.

After searching through the forum, it seems that this would be the symptoms of a bad alternator. Could is be something else causing this? Is there anthing else I should check before going out to buy a new alternator? Any help would be greatly appreciated.

Thanks,
George

Could be your battery - how old is it? Have you had it tested lately? If the battery is gone, the best alternator in the world isn't going to help.

If you have another car with a good battery, I'd swap them and then put a multimeter on the car and test loads while idling.

The battery is probably at least a few years old. I can't remember when I put this one in but it's been awhile. I will try to swap in a good battery and see what happens.

Thanks,
george

When that happened to my 91 300SE it turned out to be a bad voltage regulator. It's a device that attaches to the back of the alternator and held by two screws. Probably under $50 from FastLane.

Sixto

Your battery is probably fine, but there is a good chance the dying alternator took it out with it. 99% sure it's your voltage regulator. It's always the voltage regulator on these cars. Grab a phillips head screw driver, unscrew the two phillips screws on the back of the alternator, and you should be able to tell what is going on.

The brushes wear and there's only so much stretch in the springs. At some point there isn't enough spring force to keep the remaining brush on the commutator(?). You'll see the contact area of the brush will no longer be shiny as it would be if it were making proper contact. You can replace it in the time it takes to read this :)

Sixto

Voltage Regulator....dont Let Them Sell You New Alternator.

It is the voltage regulator. Replace it and have your battery charged and you should be good to go.

You can buy a new VR for about $14 by clicking on fastlane above. These are good VRs. I've run one for several years now with no trouble.