Engine coolant temp light and Dual Alternator questions

[dodger73]

Is the engine coolant temp light supposed to light up when you turn the key on a M1008? I'm not referring to the low coolant light because the manual does state that that light should come on (which mine does) but the manual doesn't refer to the engine coolant temp light. Mine doesn't light up but not sure if it should or not.

Also what is the purpose of the dual alternators? And is one 12 and one 24?? Or are they both 24's???

Thanks!!

 

[camogriz]

I believe that all the dash indicator lights should come on momentarily when starting up in order to verify the lights are all working. The dual alternators provide 24 volts to the starting system. It also makes it possible for all tactical vehicles to be able to jump start each other out in the middle of no-where. If some had 12 volts and others had 24 volts it would be interesting to say the least. Kind of an idiot proof design. The military radios commonly installed in these vehicles also require 24 volts. The lights are all 12 volts. The glowplug system gets power through a large resistor on the firewall which reduces the voltage from 24 to 12. Both alternators are 12 volts, but I think they are special- externally grounded. The drivers side alternator charges the front battery and the passenger side alternator charges the rear battery. The alternators are both the same and are interchangeable. Hope that helps.

 

[Keith_J]

Yes, alternators are isolated ground. Alternators produce alternating current, this is changed (rectified) inside the alternator by a diode bank (6 diodes, alternators are typically 3 phase). In the Delco alternators, the diode bank is normally grounded negative to the case. In the CUCV alternators, the diode bank's outside heat sink is isolated from the case and connected to a second insulated terminal on the rear.

The TM's charging system diagram is slightly mislabeled, alternator 2 is captioned "Both batteries charging" but in reality, it only charges the rear.

 

[Warthog]

Welcome to the site.

Make sure you go to the "CUCV Helpful Threads" page. It has a bunch of stickies that help explain how the CUCVs work. Also download the FREE technical manuals for the trucks.

http://www.steelsoldiers.com/showthread.php?123199-CUCV-helpful-threads