Protective Control Box schematic?

[VULCANGUNNER]

Does anybody have a wiring schematic for the M939 Protective Control Box?

I design power distribution systems for heavy equipment & would like to know exactly what is going on inside that box without gutting mine, just in case I need to replace one or somebody else needs a replacement / upgrade.


Thanks

 

[Suprman]

At one time I uploaded a picture. There are 2 relays and a diode. If you download the p2p I believe it has a schematic. I wanted to rebuild one with heavy duty solid state relays I found some dc ones that are good for 120 amps I am not sure if it's enough though. I did consider doubling them up.

 

[KsM715]

Some one had a hand drawn schematic ( can't remember if it's for the m939 or m809 series) I'll see if I can find it. In the meantime try BFR metals down in Salina, they have been scrapping quite a few trucks out of Riley and probably have a few control boxes you could get to tear apart.

 

[doghead]

http://www.steelsoldiers.com/showthread.php?113634-Ever-see-inside-the-Protective-Control-Box

 

[aheilmann68]

I the ones I have fail have printed circuits boards. One had terminal corrosion that led to bridges and failed diodes and resistor andnthe other had a faioed diode and resistor due to overheating. Cranetruck did a bare bones version that only protects against reverse current and does not take in to account neutral position (900) and an oil pressure cut out (900&800)