Not charging in neutral

[Jmech]

M1078A1, 2320-01-447-6343 MFG. Date 09/05. Truck will not charge when in neutral. When you put it in Drive or Reverse both 12V and 24V show good charge. Charging system light stays on all the time.

 

[simp5782]

M1078A1, 2320-01-447-6343 MFG. Date 09/05. Truck will not charge when in neutral. When you put it in Drive or Reverse both 12V and 24V show good charge. Charging system light stays on all the time.

What is your voltage at the batteries using a meter? Don't trust the gauge

Both of your alternator lights blinking green?

 

[Jmech]

What is your voltage at the batteries using a meter? Don't trust the gauge

Both of your alternator lights blinking green?

This is the alternator that doesn’t have the flashing lights. Batteries are all good.

 

[simp5782]

This is the alternator that doesn’t have the flashing lights. Batteries are all good.

What is the voltage in neutral vs that in drive on a meter?

 

[Ronmar]

What is your oil pressure idiot light doing? K11 provides the power to enable the alternator when it is DE-ENERGIZED. On the A1, The neutral relay(K26) provides the power to energize K11, and the 15PSI oil pressure switch provides the path to ground to complete the circuit to energize K11 and disable the alternator. This happens when you turn on the main switch, K26 energizes and powers K11 which energizes because the OPsw is below 15PSI(also lights the low oil p light in the dash). When you start the truck, the OP goes over 15 PSI, the switch opens, the low oil light goes out, and it also opens that circuit to K!1 so it de-energizes, enabling the alternator.

So if the neutral relay is controlling K11 and the alternator, the oil pressure switch circuit is shorted…

 

[Jmech]

What is your oil pressure idiot light doing? K11 provides the power to enable the alternator when it is DE-ENERGIZED. On the A1, The neutral relay(K26) provides the power to energize K11, and the 15PSI oil pressure switch provides the path to ground to complete the circuit to energize K11 and disable the alternator. This happens when you turn on the main switch, K26 energizes and powers K11 which energizes because the OPsw is below 15PSI(also lights the low oil p light in the dash). When you start the truck, the OP goes over 15 PSI, the switch opens, the low oil light goes out, and it also opens that circuit to K!1 so it de-energizes, enabling the alternator.

So if the neutral relay is controlling K11 and the alternator, the oil pressure switch circuit is shorted…

Thanks for the information! We will dig into it tomorrow!

 

[coachgeo]

Hopefully it is as Ronmar is pointing out and not that you only have high enough oil pressure when RPM's go up.

Which maybe points out another test if you have not done so (or I fubared and didnt read well).... bump up the rpm's when your in neutral and see if that changes anything