M1009 7-way Trailer light upgrade

[kallisti5]

I generally want to keep my M1009 as stock as possible (maybe converting to a flat olive paint job), but one thing I've wanted to do for a while is improve the trailer connectivity.
I really didn't want to hack in a bunch of 4-way trailer splices, and definitely didn't want to disconnect or otherwise tamper with the military tow connector.

Came up with a nice solution which looks like it belongs
I double checked the trailer voltage and it is 12v. I assume that is stock? (I thought trailers were 24v... could be just wrong though)


I cut a hole around the same location and size as the original military socket.
(figured if the original one was strong enough, placing it identically on the other side would be strong enough.
You could re-enforce with a piece of metal welded on the back side, but that plate is pretty thick and these
things won't tow *that* much.




I created a harness to plug-in to the stock connectors for the military trailer socket.
The harness just taps the wires and branches them off for the new 7-way socket.




With a 7-way to 4/5 way adapter plugged:





Done:




No more messy dog-bone adapter:




Parts: (~$64)
* 3-way GM connectors - https://www.amazon.com/gp/product/B07BJKNGJK/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 $14
* Trailer wire - https://www.amazon.com/gp/product/B000CQQKNI/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 $12
* 4/5 way adapter - https://www.amazon.com/gp/product/B0049MTHTA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 $17
* 7-way connector - https://www.amazon.com/gp/product/B009F5D81O/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 $21

 

[MarcusOReallyus]

Came up with a nice solution which looks like it belongs
I double checked the trailer voltage and it is 12v. I assume that is stock? (I thought trailers were 24v... could be just wrong though)

Just wrong.

Except for the GP and starter circuits, the vehicle is 12v.

Nice solution, and thank you for posting the parts!

 

[48cj2a]

Trailer voltage is really only determined by the bulbs.

Back in the 80s when we were using M101 style trailers with our CUCVs we just swapped out the bulbs to ensure there were good and bright.

 

[kallisti5]

Trailer voltage is really only determined by the bulbs.
Back in the 80s when we were using M101 style trailers with our CUCVs we just swapped out the bulbs to ensure there were good a bright.

Ah. That's what confused me. I have a M101 trailer that was "modified" to work with the M1009. I assumed it was the other way around (12v modified to work on the 24v)

 

[48cj2a]

You gotta remember the M101 is Korean Heritage originally designed for the M37 Dodge which was 24v.

Been too long since I've been around the Dodge 800 series 5/4 tons but I think they were 12v too.

Just look at the wheels to see what generation it was meant for. Later rims look like the modern pickup 3/4 - 1 ton 8 lug versus the Budd type.

Later variants may have come 12v ready by design.

We still have at least a dozen M101s on base here as they are slowly being replaced by the M11XX series trailers.

 

[acthomp781]

Nice Job!

 

[MarcusOReallyus]

Trailer voltage is really only determined by the bulbs.

Back in the 80s when we were using M101 style trailers with our CUCVs we just swapped out the bulbs to ensure there were good and bright.

Yep. My trailer had 24v bulbs in it when I picked it from from Ft. Meade. The lights worked, but they were dim. I swapped in 12v and it's been happy since.

 

[Tinstar]

That turned out really nice.
Perfect location and looks good.
Paint it OD to match and most will never notice new plug.

Yea
I initially thought and assumed the stock CUCV trailer plug was 24v.
Quickly Learned otherwise.