M915A1 tractor to trailer cable

[Westech]

can i use a civy 7 pin cable with a 915 and a 871 trailer or do i have to use this cable? I do not have one and SW needs to move my junk.

Thank you

 

[markmontana]

I think you need to use that cable in the picture. That trailer should have the 24v connection only. I'm pretty sure.

 

[Westech]

no its has both.... so the question still stands

 

[markmontana]

Your 915 has a 12v cable connection and if the trailer also has one (and it's functional) you can do it.

 

[Ferroequinologist]

yes, you can use one or the other. depends on the trailer, as Mark has said.

There are problems with the 12v lighting on a m915, they take a lot of load for some reason. My light switch failed after a long night pulling a civi trailer- for a year previous I've used the 24v and never had an issue. If I were you I would run the 24v. Takes some load off the 12v side.

 

[markmontana]

Here is the cable you can use for 12 v on 915
Electrical Connector Umbilical Cord, Truck 18-Wheeler P | eBay

I have run my 915 with this 12v type cable no problems yet

 

[Bighurt]

I use a standard one, but I have a modified light switch.

 

[EMD567]

I thought your tractor was charcoal??????

 

[groundog]

THE 12V CABLE SALES FOR 40 DOLLARS IN THE PHOENIX AREA

 

[gpcpilot]

You may want to check your local NAPA. Mine sells the cable for $11 for the 12v version that plugs in right behind the driver side of the cab.

 

[LanceRobson]

Ferro, I suspect the issue is that the GI trailers don't have running and clearance lights so a civy trailer is drawing a lot more amps than a GI trailer with just tail lights. I guess you could use the regular light switch to trip a relay and let the relay carry the load.

I'll have to ask my in-shop electronics wizard...

Lance

 

[gimpyrobb]

Rich, I'm pretty sure I have the umbilical cord, if not, we can use my tow light setup.

 

[goldneagle]

You may want to check your local NAPA. Mine sells the cable for $11 for the 12v version that plugs in right behind the driver side of the cab.

The connector sells for more than that!

 

[11Echo]

Ferro, I suspect the issue is that the GI trailers don't have running and clearance lights so a civy trailer is drawing a lot more amps than a GI trailer with just tail lights. I guess you could use the regular light switch to trip a relay and let the relay carry the load.

I'll have to ask my in-shop electronics wizard...

Lance

The M915's are considered cargo transport trucks and used as such as opposed to combat vehicles. Clearance and running lights should not pose any problems. My equipment/military semi trailers all have running and clearance lights. Some have both civilian and military plug outlets.
The MK17 I pulled yesterday also had a complete compliment of lights.

Plenty of lights on these trailers.
The flatbed behind the MK17 in the last pic had both outlets on it.

 

[Autocar]

I have almost the identical setup. I pull an M871 with an M915A1. I use the standard civi 12V cable. Have not had any problems. Electrical loading will be the same with either 12V or 24V. The only advantage to the 24V is that the trailer is getting it's power from relays instead of going thru the light switch, which other posters have said seems to be a weak link.

 

[Old Lincoln County Iron]

I pull my two M871 trailers with my two M915A1 tractors using the 7 pin commercial cables. I have the military 24 volt cables in the trucks aswell. I also pull these trailers wits my two M931 tractors using the 24 volt military cables.I have ha ex pretty good luck so far. I have converted the M871's over to nearly all led lights which I think is the way to go, slot less current and much longer life.