M916a1 charging issue

[Craftsman17]

I have a m916a1. The issue I'm havin is only the rear set of batteries in the box are charging. Tested the rear battery's and they see 16-17v while tell truck is running, checked the front and they are sitting at 10v, the gen is putting out 28v and each of the 3 posts are at 14v. Not sure what else to look at from here. Have swapped the battery's with new all the way around and still have the same isssue

 

[simp5782]

I think artisan has some electrical system diagrams for the 916s in his build thread. You may scan thru it or PM him directly.

All I can say is that you need to track the cables back on the batteries that aren't getting enough voltage and see what they hook to and check for voltage at that spot. May just be a bad connection some where. Poke and prod along with your multimeter on those wires.

http://www.steelsoldiers.com/showthread.php?122713-Artisan-s-M916

 

[Castle Bravo]

I'm not terribly familiar with the M916A1 charging system, but I would start by looking into the electrical troubleshooting section of the unit maintenance technical manual. (TM 9-2320-363-20-1) The electrical troubleshooting section starts on page 3-11 and shows the following sections -

ELECTRICAL SYSTEM
CHARGING CIRCUITS
1. LOW BATTERY VOLTAGE
2. BATTERIES NOT CHARGING (EITHER VOLTAGE), VOLTMETER INDICATES VOLTAGE
3. BATTERIES NOT CHARGING, VOLTMETER DOES NOT INDICATE VOLTAGE
4. +12 VDC CIRCUITS NOT CHARGING, +24 VDC CIRCUITS NORMAL
5. +24 VDC CIRCUITS NOT CHARGING, +12 VDC CIRCUITS NORMAL

I would suspect you may be able to find out some information in there. The manuals for these trucks contain information for the M915A2, M916A2, and M917A2 as well as your M916A1, so be sure you're looking at the correct information.

I think artisan has some electrical system diagrams for the 916s in his build thread.

Artisan's thread is good, but it has info about the AM General M916, not the Freightliner M916A1, which is significantly different in the electrical/charging system department.

 

[MAXMAD]

I too am having charging issues with my m934. Its overcharging and cooked my 4 batteries. Looking for a 5 ton mechanic in palm coast area of fl. Im living in az and truck is at friends house. Ned to get fixed asap