Keith Browning Posted April 3, 2013 Share Posted April 3, 2013 With regard to trailer wiring and connectors of all types, would we all be in agreement that there is a "standard" when it comes to the pin/pole positions and the circuits involved? At least I have always known this to be true. So I have a 2000 F450 in a week ago and they asked to repair the trailer wiring. The failure was the result of splice connections that were not weather sealed... corroded and broken wires. I am sure we have all seen that. The wires leading to the connector from the factory harness had been spliced up several times over the last 13 years and changed color as many times. And I could not figure out why there was a relay powering one of the circuits powered by the battery charge circuit. Just a Bosch relay, hanging upside down with exposed and corroded connections. I cut it all out. Installed a new trailer connector, fabricated a new harness between the connector and the factory trailer tow harness on the frame sealing all splices with heat shrink with sealant and packed the connectors with dielectric. I verified the operation of all circuits with my Phillips trailer wiring/trailer brake simulator. All good. A week later the truck returns. A short Portuguese "mechanic" get all huffy with us and doesn't speak a word of English. Translator was present. "The parking lights are on all the time and the trailer brakes don't work" but this only happens when the trailer is connected to this truck!!!!!!" Long story short the trailer wiring is incorrect on the trailer... as are all of this other trucks. The running lamps are connected to the 12V supply... the brake is wired to the parking brakes. Yep. I fucked up. He brings down his GMC... half the lights don't work on the truck and none of the lights on the trailer don't work. It MUST be me! What is worse is they have other trailers and trucks trucks. Anybody want to wager on what they are going to "fix?" Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted April 3, 2013 Share Posted April 3, 2013 I agree there should be a standard, but I have seen varitions between trailer builders. I normally ask to have a trailer brought with the truck if I have any doubts about the trailer being the issue, or if the customer continues to have issues. This is where I get my wiring info... http://www.etrailer.com/faq-wiring.aspx Quote Link to comment Share on other sites More sharing options...
Buddy_M Posted April 3, 2013 Share Posted April 3, 2013 The standards that e-trailer lists are nice, but they miss a few points. The round 6 pins have two different setups, as the trailer brake and 12v pins can be swapped(as Phillips and other manufacturers make an adapter from 7 pin flat connectors to use either way if brakes do not work properly). Bargman is one plug brand that lists the wire colors completely different on their 7 pin flat connectors, if you ever look at the rear of an aftermarket plug/socket when wiring, they will list green for tail, red for left turn, brown right turn, etc. Only common with Bargman is blue, white, and black wires which can make it confusing when dealing with different trailers or people who may have messed with the trailer wiring. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted April 3, 2013 Share Posted April 3, 2013 From memory - if you check into it, I think you will find that the round 7 pin connectors are generally used for heavy trucks. I have no idea standard, accepted wire assignments are, but they are easy to find on the 'Net. What we encounter in our store are the 7 pin connectors with the flat pins and the wiring assigned to conform with accepted "holiday trailer" wiring. This works great - as long as some dork doesn't come along and rock the boat. We need to remember that wiring seems to be hard on most techs - experienced and neopyte alike - let alone what it must be like for some knuckle dragging truck pointer. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted April 3, 2013 Author Share Posted April 3, 2013 Every time I get a replacement connector though, the documentation weather it be the label or a piece of paper in the package tells you which wires are for what and the wire colors on the part are FOR REFERENCE ONLY to identify the circuit. As a matter of fact, I still have it and it states: "NOTE: Locate wires and pin location by function only. Color coding is not standard among all manufacturers." The nice diagram and color coding seems to be more concerned with pin position and function than anything else and tells you what pin is supposed to do what. This matches what Ford has published and everything else I can find so far. Now, realistically, anyone can wire these things up in any order they please and as long as everything matches between the trailers and tow vehicles being used then all is well... except when situations like this arise. One reason I can see for intentionally doing this is to make theft more difficult or a pain in the ass... you can put the 12V battery charge to the electric brake pin and hope that a "properly wired get-away truck" will cause the brakes to lock. Assuming that will work. Quote Link to comment Share on other sites More sharing options...
mrbudge Posted April 3, 2013 Share Posted April 3, 2013 Whenever I do a wiring repair on a truck, I make it very clear that I will make the truck work as intended. If the trailer is not present I cannot guarantee the functionality of the trailer. I have a 7 pin trailer emulator which I consider standard for pin locations. Wiring colors do not really concern me as long as the pins are connected properly. I recall one customer who insisted there was a problem with his new truck because whenever he plugged in his trailer the running light fuse would blow. I convinced him to bring his trailer, and when plugging it in you could hear the arc in the connection just before the fuse blew. I offered to trace and repair his wiring concern in the trailer, at his expense, to which he mumbled something about him having a guy to take care of it. And even after all of that I was still an asshole because the fault with his vehicle wasn't warranty and I told him so. Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted April 3, 2013 Share Posted April 3, 2013 Phillips and other manufacturers make an adapter from 7 pin flat connectors to use either way if brakes do not work properly I have seen adaptors that have a switch that will change the center pin function. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted April 3, 2013 Share Posted April 3, 2013 What you need is a trailer emulator. Tekonsha makes one that is reasonably priced. Make sure you get the one compatible with ABS. Simply plug it in at the back of the truck, operate the lamps and watch the LEDs. Caveat - many trucks that have had wiring repairs in the past may have "shed" functions such as back up lights, interior light or battery charge provision - check with your customer regarding his needs. Using an emulator is quick, easy and removes all doubt. Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted April 3, 2013 Share Posted April 3, 2013 Using an emulator is quick, easy and removes all doubt. It does. Unless the truck has been rewired to match a miswired trailer... It's the chicken vs. the egg all over again. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted April 3, 2013 Share Posted April 3, 2013 Here's the rub.... I can rewire the rear apron on your truck to what is "industry standard" relatively quickly and economically - depending on what has been left behind. The minute I have to start replicating bullshit, the clock starts running in earnest. 1 Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted April 4, 2013 Share Posted April 4, 2013 Just recently, I had an issue with a truck that had been "rewired" to match a miswired wood chipper(7 way, flat)... The stupid thing is the fact that the trailer shop rewired his truck to fit his new wood chipper-but, for some reason, he was having issues with his other trailers afterwards... I suggested to the customer that there was a pin out of place in the trailer plug, and he asked if I would rewire the truck to where it should be, and rewire the trailer plug... You'd be surprised at how well that worked! 1 Quote Link to comment Share on other sites More sharing options...
DieselD Posted April 4, 2013 Share Posted April 4, 2013 I always correct the vehicle to operate as its was intended. That is the standard IMO. They need to be wiring the trailer to work with their vehicle and not the other way around. I have delt with alot of trailer wiring issues and each and every time its some hacked up mess causing the issue Quote Link to comment Share on other sites More sharing options...
YukonTyler Posted April 4, 2013 Share Posted April 4, 2013 Up here we get trucks from all three levels of government. The worst of the three is the City of Whitehorse. Their tenders get switched from the stock 7-pin to a Pollack 6-pin. That's no big deal, but the silly thing is that on each tender they bring in a printout on 'City of Edmonton' letterhead with the regular Pollack schematic scratched out and wires rearranged. Sometimes you just have to shake your head. I don't understand why you would go from a popular standard to a rare standard to just straight wrong. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted April 5, 2013 Author Share Posted April 5, 2013 I see your government is just as fucked up as ours! Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted April 5, 2013 Share Posted April 5, 2013 That's 'cause they're in the dark for half the year and the rest of the time they are fending off black flies half again as big as warthogs Quote Link to comment Share on other sites More sharing options...
Aaron Posted April 5, 2013 Share Posted April 5, 2013 That's 'cause they're in the dark for half the year and the rest of the time they are fending off black flies half again as big as warthogs Quoted for truth, and been there, done that, f*ck that. Quote Link to comment Share on other sites More sharing options...
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