barrman : Trailer Plug

Trailer Plug
Post by barrman on Aug 24, 2006, 1:32pm

My quest for the last few weeks has been stock wiring. Most of my stock wires are still on the truck. The fire department just ran wires next to them, added switches and cut off the ends of the stock stuff when something didn't work. I now have all the pieces needed to go back to all stock wiring for the the lighting system. My students have made a bench top "mini" lighting system over the last week or so. We figured out that my 3 lever switch is bad, but only on the blackout lights circuits. It will do until I get another one. I have 4 students each sanding on a different light bucket as I type this. I hope to paint them this weekend and put the guts back in. Another student is working with a hammer to straighten out the frame ends that hold the rear light buckets. This will let me return the rear of the truck to completely stock lights and wires. Except for the trailer plug.

I have all my trailers set up for the round 6 pin civilian trailer plug. My M715 has this on it as well. Is the 12 pin military plug specific to only military uses or does it have a civilian equivalent?

I saw a military trailer pig tail on e-bay the other day. I didn't see any recepticles. Anybody have both that they want to get rid of?

Re: Trailer Plug
Post by tacomainoh on Aug 24, 2006, 4:06pm

what goes bad in a 3lever switch???

Re: Trailer Plug
Post by 40grit on Aug 24, 2006, 4:15pm

if you can pull the 3 lever apart, I'd clean up the contacts inside...I'd guess you got some "crud" on the BO terminals


maybe even just cycle it a whole bunch of times, it may self-clean...

Re: Trailer Plug
Post by brute4c on Aug 24, 2006, 4:30pm

Depends...some have a plastic interior that cracks/breaks internal parts....the unlock lever can fall out of its place and short the switch....wire connections, solder points, internal resistor....I know theres more...

Re: Trailer Plug
Post by tacomainoh on Aug 24, 2006, 4:40pm

so simple, obvious stuff that should be fixable? schweet.

Re: Trailer Plug
Post by brute4c on Aug 24, 2006, 4:45pm

The ones with the plastic guts have a seal that basically you have to break to get into the switch...and then if the plastic parts are the failure point, not sure that they can be gotten seperately....they suck...I had one and I dissected it and posted pics some time back, now lost, of the cheapo interior...within 2 months of getting it, the headlights wouldnt always come on....the plastic cam was slowly bending inside and not letting the contacts touch....

Re: Trailer Plug
Post by fisherman on Aug 24, 2006, 11:56pm

By receptacle you mean the plug on our trucks the trailer plugs into? I have one of those I probably won't be using that you could have.

Re: Trailer Plug
Post by barrman on Aug 25, 2006, 8:52am

Tacoma,
Here is what I am getting on the bench top with the current switch:

TOP LEVER
"Stop Light" does not give power to either brake switch lead but, does allow the blinker system to work.

"Service Drive" give me head lights and tail lights like it is supposed to but no dash lights no matter where I turn that other lever.

"BO Marker" Transfers no power anywhere except to the dash lights.

"BO Drive" is the same as BO MARKER

The "lock" lever just turns. It doesn't lock anything.

Aux SWITCH

Turning this one to Park gives me running lights at all 4 corners and allows the blinkers to work.

As long as the Main switch is on one of the BO settings, the "Panel Brt or Dim" works like it is supposed to.

That is how it worked on Tuesday. Now, the "Park" setting has to be hunted for and I can hear an arc inside the unit if I play too much. Obviously, the switch is bad.

I have left my "bench" setup intact until I can get a picture of it. That will happen when my students leave in about 20 minutes. Then I will try to take the switch apart and my next group of students are going to cut a hole in the dash to the left of the steering column for the switch to mount.

Fisherman, PM coming.

Re: Trailer Plug
Post by brute4c on Aug 25, 2006, 10:55am

The unlock lever, lower right of the 3 lever light switch, is there to keep the top lever from moving when one doesnt want it to. Basically the top lever, on the inside of the 3 lever housing, has several teeth....the unlock lever is connected to a strip of metal that fits into one of those teeth...when the unlock lever is lifted, it pulls the metal strip, which is connected to the far opposite edge of the unlock lever, down...thus pulling the opposite edge of the metal strip out of whichever toothed recess in the top lever it is in. Then the top lever can be moved to whatever position and the unlock lever released, thus putting the metal strip into one of the other toothed positions on the top lever....

A pic would be so much easier....I wish I could draw....

Anyway, if one repeatedly moves the top lever without lifting the unlock lever, the chance is much higher that the metal strip on the unlock lever will become disconnected from the unlock lever and then you have a long metal strip moving around freely inside of the unit with metal connections, some live, all over the place...for those who have had a switch that shorts out and you hear the loud click of the internal circuit breaker, then you hit the switch and things reset after a bit, this is why.

So, in a properly working switch, the unlock lever does do something...one can test to see if the unlock lever is working properly by attempting to move the top switch with the unlock lever lifted and without...if it is much harder to move when the unlock lever is not lifted...perfect...if it makes little or no difference, it could be a problem soon...if not already. I wouldnt recommend doing this very often though....

I know that wasnt your problem Tim...just sharing the little seed knowledge that I do have....

Re: Trailer Plug
Post by brute4c on Aug 25, 2006, 10:58am

Hmmm...maybe it is part of your problem....you can take them apart from the rear....just be very careful not to dislocate all those little metal pieces in the front part of the unit....

I have to wonder about your unlock levers metal strip being loose due to your "I can hear an arc inside the unit" comment...

Re: Trailer Plug
Post by barrman on Aug 25, 2006, 3:36pm

I took it apart since the above post. The "contact board" which the different levers move the contacts against was all burned up. Lots of visible arcing signs. This has to be why the fire department started hacking up my wiring all those years ago.

The unlock "arm" was still attached and had places to engage the main switch. The unlock lever and arm are connected by a bolt with a nut on it. That nut was about 1/2 turn from falling off. That is why the unlock didn't work. I also had a lot of little black plastic pieces floating around inside the switch. Basically, it was toasted.

Re: Trailer Plug
Post by brute4c on Aug 25, 2006, 3:47pm

Wow...yours was nasty.....glad there was no fire!!

Interesting yours had a nut holing it on...one I had was a funny spring clip setup....clip broke...I dont remember what the plastic gut housing had....I have dissected 2...

Re: Trailer Plug
Post by barrman on Aug 28, 2006, 8:00am

Here is my "bench top" wiring set up. My students learned alot about converting a schematic to reality with this one. The 3 lever switch is still a mystery to some though.

http://img147.imageshack.us/img147/5...hwiringcq6.jpg

These are Duece light buckets in the picture. I painted them over the weekend and they are now my working backup light system ready for installation if the local law enforcement people don't like the little bitty stock light lenses.

Re: Trailer Plug
Post by binfordm715 on Aug 28, 2006, 8:56am

They can "not like them" all day long here, but they're stock for that model truck so......

Re: Trailer Plug
Post by barrman on Aug 28, 2006, 9:10am

I agree Tim. But, we have state inspections here. I have the hardest time getting the M715 inspected it is amazing. "These tires (NDT's) aren't street legal", "Steering too hard to turn", "You added power steering so I can't pass this truck", "That is not the stock engine so I can't pass you", "You can't have a convertable truck in Texas", "I can't pass this truck with the headlights so high and the lift kit you put on here", "You have to have amber front turn signals for me to pass this truck." These are all things I have been told in the past 5 years trying to get it inspected. Everytime I find an inspector who likes it and will pass it without question, he gets busted for not being tough enough by the state and I have to drive around and find somebody else friendly. Mind you, there are currently only two places in my town that do inspections. I have driven 40 miles before to get inspections. I am going to present it next June when it is due with the small lights and see what happens.

Another problem is our small town police force. I was pulled over last fall for having my license plate too high behind the bumper. The officer had trouble reading if a Z was a Z or a 2. He gave me a warning. I unbolted the plate and hung it way down from zipties. The next week, the other officer working days at the time pulled me over for having it too far down. He gave me a warning as well. I nicely told him to check with the other guy and figure out what they wanted. I left it hanging low and haven't had trouble since. I anticipate trouble from the small lights either with the inspection or on the road. If the state didn't have the "parades and other special events only" clause in the former military vehilce license catagory for usage, I would get that and not worry about plates, plate lights or inspections at all.

Re: Trailer Plug
Post by binfordm715 on Aug 28, 2006, 9:52am

Crikey! And you Texans actually put up with that crap?! I thought y'all were a bunch of rebels down there!

Nice not having vehicle "inspections" here. But we'd better hush up about it or our governor might get a great idea for yet another fund-raiser here.

Good luck, Tim!

Oh, how often do you have to get it inspected?

Re: Trailer Plug
Post by barrman on Aug 28, 2006, 10:13am

The $12.50 I spend for inspection gets me a sticker on my windshield that is good for basically 13 months. I agree about getting rid of it. Oklahoma just got rid of theirs in the last year or so. The problem is all the Kalifornia transplants around here now. Them and all the other people who believe the purpose of the government is to make everybody safe and not let any harm come to anyone.

I have been trying to talk my school into letting me get my class licensed as an inspection station. Then I can inspect my own stuff. Everybody approves of the idea. Just haven't gotten approval for the $2,200 needed to make it happen. Sep 1 is a new fiscal year for us and it could happen this year.

Re: Trailer Plug
Post by wrecker on Aug 28, 2006, 11:30am

Tim, I removed the shaded parts of my taillights on the bar section in order to get more visibility out of them. Now I have a straight bar of light and the oval. Looks like original with a little more light coming out of em. Since all three bulb sockets are for single pole bulbs, I wired them a couple ways to get the look I liked. Oval stop and turn w/bar as marker light, and vise versa.

Re: Trailer Plug
Post by barrman on Aug 28, 2006, 11:47am

My fronts are like that with everything clear. That is why I got hassled about the no amber turn signal a year or so ago.

Re: Trailer Plug
Post by oilcan on Aug 28, 2006, 12:33pm

Tim, I'm running the same lights as the ones on your bench there, except I'm using front housings all the way around for a tad more ground clearance in the back. It's nice that the lenses interchange.


I hope you get your inspection sation, but keep working on getting rid of that whole bureaucratic mess.