Trailer lights and the M-715...

[Snuffy]

Anyone know if the side marker lights (amber, red) for a trailer will cut off if you flip the light switch to 'blackout' on the 715??

I'm not an electrical guru... so, I would figured I would ask.

[Barrman]

John,

No, the running lights on a civilian trailer will only work with the service lights on.

As I am sure you know, a civilian trailer only needs 4 wires to work. 1 for the running lights which includes the tail lights and side marker lights, 1 for a left blinker which is also the left brake light, 1 for the right blinker/brake like and then a ground wire. Civilian electric trailer brakes requires another wire as does a constant power to the trailer for stuff like dome lights or something like that. That gets you up to 6 wires.

Now, the military trailer plug has 12 pins. The same basic 4 as civilian stuff plus b/o lights and b/o brake lights. The other 6 pins vary by vehicle series as to whether they are used or not.

First, you have to find a military trailer pig tail and plug. It is better to find a complete one with the packard ends on it. That way all you have to do is put the proper opposite packard connectors on your trailer and you can swap out plugs depending on the vehicle pulling the trailer at the time. Or, you can do like I did and put a normal 6 pin round civilian plug on the trailer end of a military trailer harness.

What ever you do, you can make the running lights plug into the b/o light pin, rewire your trailer so they are not part of the tail lights anymore and go. You won't be legal going down the road anymore, but you could do it.

[Snuffy]

Thanks, Tim!!

I figured it was something complicated... .

I had planned on rigging a trailer with mil. side marker and rear lamps. You answered everything I needed... I think!