Slave Hook up on rear

[halftrack78]

Ok, I get that it's for a trailer hook up right? But why so many pin connections, would 4 or 5 not have been easier? What other purpose did it serve? Any point in hunting down a slave cable if so where?
Thanks Everyone

[randyscycle]

The reason for all of the pins was to power all of the blackout functions on the trailers as well as regular running lights, brake lights, etc.

[halftrack78]

I guess that was too obvous.

[Barrman]

That plug was developed at least before 1952. They were just then thinking about blinkers on MV's. They wanted to plan for anything else that came up.

[k8icu]

The socket is mill standard which means it is used on all trucks for all trailers so not only can they hook up stop, tail, left and right turn, black out marker, black out stop, but also run 24V for things like trailer lights, or a heater etc.

[halftrack78]

So unless you have a slave recepticle in the engine compartment they are not able to be used to jump start correct?

[Barrman]

The 12 pin connector with the 12 gauge wires on the back is a trailer plug.

The one with the screw on cap, two huge female pins with 2 guage wire coming out the back and battery terminal type ends on it is the slave cable hook up. They can be located anywhere on the front fenders or behind the doors of the cab on the M715. The M37 had them on the front of the bed inside the bed. M35's have them on the passenger side rear of the cab. M38A1's had them on the passenger side between the door and the front fender. CUCV's had them inside the grill near the marker lights.

There are two styles. 2 pin female which everybody calls the "old style" and a single huge female called the "NATO" style.