Trailer Light Problems

[bp m1009]

alright so i bought a T harness for my m1009 from Curt Mfg. so i can have a 4 pin flat connector for my civy trailer. i later found out i bought the wrong T harness i bought one for 85 and up when i need one for pre 84 or w.e. But anyway i decided to make it work by taking out the pins from the two weatherpack connections and putting them into the t harness connector. after i got it all hooked up when i have the running lights on and i put a blinker on all the lights on my trailer flash and when i step on the brake all the trailer lights go off? anyone have any suggestions?

 

[Midnight Rider]

Why didn't you just return that and get the correct one? That seems like it would have been the easiest and best solution.

My suggestion would be go buy the correct harness.

If you don't want to do that, then I would double check your connections. You've probably connected a wire into the wrong spot. Did you just pull the cable apart and plug it in where ever you could, or did you get a diagram of the harness and try to connect everything up into the correct spot?

Perhaps the flasher has gone bad in your circuit box? I know I need to buy the heavy duty flasher for mine because currently the lights all blink really fast when I have a trailer hooked up.

I believe the wiring diagrams have been posted on here before somewhere.

 

[doghead]

Document what you have done(like tell us the connections you made) and maybe we can help.

Bad or no Grounds are the best choice, if you have all your connections correct.

 

[armytruck63]

I agree with Doghead. With a bad ground, all kinds of weird things happen with trailer lights.

 

[ida34]

This brings up a good point that people sometimes forget. These trucks were accepted by the military in 1984 and part of the contract was not to do the yearly upgrades for the parts. A 1986 cucv will be built with 1984 spec parts. Even the correct T harness did not work correctly for me. I had to run a line for the right brake and turn separately. I think the military harness is slightly different in some way. I second what Doghead said. Bad grounds will make funny things happen like what you describe.

 

[armytruck63]

This brings up a good point that people sometimes forget. These trucks were accepted by the military in 1984 and part of the contract was not to do the yearly upgrades for the parts. A 1986 cucv will be built with 1984 spec parts. .

Not to hijack, but ida34 is correct. I found out the hard way, while I was under the vehicle, that my 1984 M1009 uses 1983 6.2L engine mounts.

 

[bp m1009]

what i did was took out the wires that were in the male 4 pin square connector of the new t harness and put the matching color wires from the existing 2 weatherpacks into the new 4 pin t harness connector so i could just then plug the other half of the new harness into it. i used the green, brown, yellow and black wires. i basically took the existing wires out of the 2 old weatherpacks and plugged the ones i needed into the new 4 pin square connector of the t harnessand then plugged the female 4 pin connector to that witch has the 4 pin flat connector (tow vehicle side) on it.