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-   -   '81-300TD-turbo-Battery Discharging (http://www.peachparts.com/shopforum/tech-help/5125-81-300td-turbo-battery-discharging.html)

Buzz Davis 08-25-1999 02:27 PM

Howdy-looking for advice on test points to try and find electrical draw in system--after a thorough charge of new, correct MB-88 battery and reinstallation, battery is dead after 48 hours or so--suspected the glow plug relay, disconnected; still discharged. Ambient temp is in 90's F--motor turns over sluggishly after initial energetic start when recharged battery is installed. Anyone suggest places I can use a VOM to perhaps check for the location of a short-? Also, how can I read the amount of charging by alternator--can a system be insufficiently charging without the "idiot light" coming on? After the car is running, the battery stays low, even with minimal electrical loads.

Danke, amigos--

Buzz Davis
jcdavis@greene-associates.com

poptest 08-25-1999 07:38 PM

How do you know that your battery is discharged? What's your voltage on your battery?

You could have a poor power connection to your starter, or a bad starter.

Benzmac 08-25-1999 10:25 PM

The car can be discharging with out the light coming on. They do this all of the time when the Alt/voltage regulator fails. Put a volt meter on the battery and start the car. The meter should go from 12 volts to higher than 13.

------------------
Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
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VA300SD 08-25-1999 11:02 PM

I believe 9 out of 10 times it's the voltage regulator. The two spring loaded contacts on the regulator eventually wears down. You could be driving around with everything running off the battery without it being recharged sufficiently. The voltage regulator is mounted on the opposite of the pulley side with two flathead screws. (There are no wires.) There are some with diodes, some without. Have to remove it to check, but it's a Bosche part. You may need a very short screwdriver if you want to get to it from the top side. Roll up your left arm sleeve up to your shoulder first...


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