low charging voltage - PeachParts Mercedes-Benz Forum

greg240d · #1 08-04-2008, 02:34 PM

Hi Guys

I just replaced my starter and alternator the starter was shot. My battery
is at 12.5 volts but when I start the car it stays around the same voltage
but when I take the termals off the battery it jumps to 13.6 volts to 14.0
volt back on the battery 12.5 volts with the car still running. Whats the
problem ? Thanks Greg

vstech · #2 08-04-2008, 02:47 PM

um, don't do that...
alternator can burn out if it's running with no load.
if the battery is good, and starts the car fine. morning voltage should be 12.76v.
the alternator should put out around 14v at idle. if it doesn't you could have a battery problem, or a serious load problem. disconnect the power lead to the starter and see if you still have an issue with the circuit. you could have a starter solenoid that is sticking.

vstech · #3 08-04-2008, 02:47 PM

what kind of alternator did you use?

yellowbenz · #4 08-04-2008, 02:55 PM

From past experience, check the belt tension. Had similar problem. New, properly tensioned belt was the solution.

greg240d · #5 08-04-2008, 03:09 PM

Thanks guys for the reply
I got it a kargen auto . I changed the starter because it had short out
the system. I also notice that the new starter hangs up a little whe I start up the
car ( grinding a little when cold ) Thanks Greg

vstech · #6 08-04-2008, 03:12 PM

so, um, what kind of alternator did kragen sell you? malaysian reman? Bosch OE? something else?
and a dragging starter is not a good thing. that could be your problem right there.

greg240d · #7 08-04-2008, 04:31 PM

Thank Guys for your help
Bad wire at the starter Thanks again Greg