View Full Version : Very strange electrical/starting problems

03-07-2013, 12:22 PM
I have an 06 2500. Only had it a few months and have not driven it much- about once every other week. Went to start it this morning-30 deg- and started fine but battery sounded a little week but not unexpected for sitting for 2 weeks

This is where it gets weird. I turned the fan to 1 after it was on 4 and it would turn the dash lights on. Turn to 4 back off. Turned the head lights on to leave and the engine stopped. It would not start up again.

Any help would be appreciated.

03-07-2013, 12:38 PM
It sounds like a problem in the charging circuit - Battery, Battery cables or Alternator - and a low voltage condition. I would put a charger on the Battery for a few hours and try to start it again - then measure the voltages at the battery terminals. It needs to be at around 12.5 Volts or above while running (more likely 13.5 or above).

Eric Experience
03-08-2013, 10:41 AM
Measuring the battery voltage is the first step, with the heater switch I would go to the bundle of brown earth wires that share the battery negative cable and clean all the lugs and the body surface. Eric

03-08-2013, 11:41 AM
Went to start it this morning-30 deg- and started fine.

Is that minus 30F or 30F or 30C

Aqua Puttana
03-08-2013, 02:04 PM
Is that minus 30F or 30F or 30C
Don't think it really matters. :idunno:

-30F = approximately -34.5C

03-09-2013, 06:12 PM
Sorry. + 30 deg F. North Ga local

03-09-2013, 06:31 PM
I charged the battery and it started up fine. It read 12.2 v when just started and 11.8 when I turned on the high beams and heater fan. Would this mean the alternator is not producing enough power?

03-09-2013, 06:45 PM
It just died after about 10 minutes of idling with the high beams and fan on. With the key still on the on position it read 11.2 v and with the key off it read 11.7. ?

03-09-2013, 06:45 PM
@ what idle speed did you get the 12.2v vdc and 11.8 vdc voltage readings?
Where did you stick your probes to get these voltage readings?
Did you read the voltage some other way (Scan Gauge II....UltraGauge EM.... what?)
If so, did you rev the engine up to say 1500 RPMs to see if the voltage increases?
If you are getting these same readings (i.e. 12.2 VDC and 11.8 VDC) with the engine revved up to
> 1200 RPMs, then yes, it would seem your alternator may not be putting out any voltage.
P.S. Just read your update.....sounds like the battery needs to be replaced. A bad cell or something that
comes up on the charger, but dies off quickly to < the voltage needed to run your Sprinters systems.
I'd get the battery tested first, and then the alternator. Both could be bad.

03-10-2013, 04:32 AM
I agree with sailquik .... your symptoms scream of "alternator not charging"
You should see over 13 volts with the motor revving to 1000 rpm or higher.

The battery may also be toast, since a fully charged battery should be 12.5 v or slightly higher (after sitting for an hour).

good luck

03-11-2013, 12:38 AM
Thanks for the advice. I am taking my battery in tomorrow to test it and will proceed from there.