Need help re-wiring my trailer!

[kamby]

Re: Need help re-wiring my trailer!

Still sounds like a short, but could be grounding issue as well. If the test lights on the plug work then its on the trailer end, could be nicked wire grounding out, or improperly wired light. Most trailer lights ground through the mounting studs, if you want to ensure a good ground some guys will run a wire from the mounting stud to the frame nearby.

When the test lights are extremly dim as well as the trailer lights it means that there is too much voltage/amps trying to pass and the blinker switch cant handle it. When u go to parts store just tell them your vehicle and you need a heavy duty flasher. Depending on the vehicle the flasher is mounted with the fuse panel, my s-10 was a different story i found it under the dash on the passenger side, just follow the ticking noise. For the most part they just pull out and you put the new on it, there bladed and usually fit in one way. Whats nice about auto zone they have directions that can tell you how to replace it and where its located. If you can change a fuse you can change a flasher switch.

Your flasher should look something like this

 

[Utahboatnut]

Re: Need help re-wiring my trailer!

If it has a tow package I would guess the flasher has been upgraded to handle it, I tow with a 99 dodge ram and have never had a problem with my trailer lights, towed at least a dozen different trailers first and last and never had an issue. Test the test light(so to speak) on the battery if its the kind I'm thinking it is they can be a bit touchy the light in them looks almost like a old glass fuse. Make sure the spring and ends are making good contact inside the test light. Once that is working as it should finish the ground issue drill a 1/4" or so hole in the trailer frame just behind the coupler scrape/sand to shiny steel install ring connector on wire and bolt into place. Once the test light has been verified clip it to the vehicle frame close to the round connector, again you may have to scrape/sand to get a good contact for the alligator clip to ground on. turn key on and, start one side signal touch the point of the pen to each terminal of the round connector until you find the correct signal(draw a picture of the connector so you can label it). Then do the same for the other signal, once identified turn key off and turn on lights do the same process to find tail lights. Once these three wires are identified you should be good to go even if you have to do a temp wire job by jamming wires into the connector for now(don't use adaptor right now) get it all wired up and see if it works as it should also make sure you have the right wires of the lights for their respective duties, dim filiment(wire) for tail light bright filiment(wire) for turn/stop. Also for now run a jumper wire from your vechicle ground right to the trailer ground(in case there is some weird ground prob in the connector) If it were me I would splice in the four flat off the wires going to the connector you have now and just bypass the whole round 5/7 and adaptor and have four flat to four flat no muss no fuss. You can tuck the vech four flat under the bumper when not in use and be good to go.

 

[NYBo]

Re: Need help re-wiring my trailer!

No I haven't yet properly mounted that ground wire to the trailer. For the test, I just wrapped the wire around the hitch on the back of the truck.

There's you're problem right there, 99% guaranteed. You aren't grounding the trailer when you do this, you are grounding the truck - to itself! That wire has to go to the trailer frame or to the ground wires at each light. You're only ground for the trailer is through the coupler and ball, dicey at best, zero if you don't have the trailer hitched up with that test setup.

 

[Biggems]

Re: Need help re-wiring my trailer!

Ok I just went out and tested the harness on the truck with a light tester and everything seems to be working good. I've attached a picture for reference. The prongs circled in RED are the regular lights and the prongs circled in BLUE are the turn signals and break. The prongs that are not circled...I have no idea what they do.

I also tested with the adaptor plugged in. Everything seems to be working fine. As I mentioned in an earlier post, with either turn signal on, the corresponding test lights on the adaptor blink very very dim. Which was cause for concern earlier. But with the juice tester, it comes on nice and bright. So maybe it's just the test light on the adaptor.

In reference to grounding the trailer for the test. I tried both grounding it to the trucks hitch and to the trailer itself. Granted it was a quick ground. All I did was wrap the wire around a metal part of the trailer tongue. Next time I go out, I'll properly mount that ground wire and hopefully it will all work.

 

[Utahboatnut]

Re: Need help re-wiring my trailer!

I think the prob may be you are using one too many hots. A four flat is basically a three wire system with a ground as the fourth. One common does the running/marker lights, one does right turn and brake, and one does left turn and brake and one does ground. I'm not sure what would happen if you used two off of the adapter for your running lights, probably create a short or a condition like what you have. When you tested was the key off and just the truck lights on? and you still had power to both of those terminals circled in red? I think one of them MAY be for interior lights for like a travel trailer and can't be used for your application. Like I mentioned go around the connector for now and get everything working once you have it splice into those wires with the vechicle portion that came with the light kit and then you have both connectors on your truck and can take the adaptor back and get some heat shrink to seal up your splice job. Also make certian on ALL of your grounds for now make a ground wire right from the truck to the trailer not through the hitch but a designated ground wire, heck if you had a decent length piece you could come right off the battery ground to be sure. plug the two four flats togather twist all of your grounds togather(truck and trailer) strip some insulation off the ends of the wires twist and fold over, then stick the respective wires right into the connector on your truck test operation of lights then you know if the adaptor is wrong or the problem lies somewhere else.

 

[kamby]

Re: Need help re-wiring my trailer!

1st pic (left) vehicle side, 2nd pic (right) Trailer plug


His is correct, the two top ones are tail lights and 12v constant.

The ground should be below the left turnsignal, the wire next to it is for elec brakes and the middle one is backup (often times the backup wire and break wire are reversed.


http://www.accessconnect.com/trailer_wiring_diagram.htm

read the faq part at the bottom, its got to be a ground problem...

 

[Starcraftguy1]

Re: Need help re-wiring my trailer!

Is that on a Dodge?

 

[Biggems]

Re: Need help re-wiring my trailer!

yeah its a '99 Dodge Durango SLT

Is there a way that I can check the ground wire on the vehicle end to make sure it is properly grounded? Or did my test with the test light earlier confirm that everythign on the vehicles side is working?

 

[kamby]

Re: Need help re-wiring my trailer!

Depends on what you grounded it too, if you grounded your light to the frame than most likely the vehicle its self is grounded properly

What you need to do is in your connector on your vehicle clip the test light to the ground post and then check your connectors, this will let you know if 7 way blade is grounded properly.

In the engine follow the negative cable, typically they ground to the engine block and grounds to the frame somewhere, but with the new vehicles and wire harnesses it may difficult to follow.

 

[Silvertip]

Re: Need help re-wiring my trailer!

Wow! 68 posts and we can't seem to get current down three wires. All of your symptoms point to a bad ground. And simply wrapping a wire around something is also not a good connection. No matter how hard you try you won't succeed until you get a good solid ground on the white wire. Paint is not a conductor of electricity so ground connections need to be electrically connected to metal. If your trailer has a tilt mechanism, that joint is a potential interruption in the electrical path back to the tow vehicle so it would be a good idea to install a ground jumper from one side of that joint to the other. If the tongue of the trailer is bolted to the rest of the trailer frame, that also represents a potential interruption so another jumper is in order. If you are concluding that running a white wire from the trailer connector all the way back to the ground wire on each light would be a good idea you would be right.

 

[Rocky_Road]

Re: Need help re-wiring my trailer!

Wow! 68 posts and we can't seem to get current down three wires. All of your symptoms point to a bad ground. And simply wrapping a wire around something is also not a good connection. No matter how hard you try you won't succeed until you get a good solid ground on the white wire. Paint is not a conductor of electricity so ground connections need to be electrically connected to metal. If your trailer has a tilt mechanism, that joint is a potential interruption in the electrical path back to the tow vehicle so it would be a good idea to install a ground jumper from one side of that joint to the other. If the tongue of the trailer is bolted to the rest of the trailer frame, that also represents a potential interruption so another jumper is in order. If you are concluding that running a white wire from the trailer connector all the way back to the ground wire on each light would be a good idea you would be right.

Post #71, Silvertip.

I suggest that he keeps the connectors...and replaces the tow vehicle!

 

[Biggems]

Re: Need help re-wiring my trailer!

lol I just got this truck less than a week ago!!

Ok i just did as suggested above and re-tested the vehicles harness with the light tester but this time attaching the ground clamp to the ground connector on the adaptor and sure enough it all worked fine. So i guess this means everything on the vehicles end is good!

Now my question is, should I drill a hole at the front of the trailer and mount the ground wire there, or should I attach that ground wire to two more long wires and run them all the way back to each ground wire for the tail lights on the trailer? If I do this, will any wire work? or is there a specific type of wire that needs to be used for the ground? If I did end up doing this, I'd like to just use some of the old wire that I pulled off the trailer before I replaced it all.

Unfortunately my boat is parked about 30 miles away at a buddy's house. (i have no where to park it here) So I can't run out and try something everytime I get an idea or you all post something. I'll see if I can get out there within the next couple of days.

 

[NYBo]

Re: Need help re-wiring my trailer!

If you run ground wires to just the two taillights, your side marker lights won't work reliably. You should be able to connect the ground to one of the coupler bolts. Use a crimp ring, don't just wrap the wire around the mounting bolt. Or drill a hole and do it that way.

 

[Rocky_Road]

Re: Need help re-wiring my trailer!

If you run ground wires to just the two taillights, your side marker lights won't work reliably. You should be able to connect the ground to one of the coupler bolts. Use a crimp ring, don't just wrap the wire around the mounting bolt. Or drill a hole and do it that way.

+1

And be sure to remove the paint beneath the two grounds at the rear trailer lights!

Have we broke the posting record yet? I want to be the one that does it....

 

[gunner1]

Re: Need help re-wiring my trailer!

Personally, I would just drill a dedicated hole maybe 5/16" or 1/4" in diameter, remove any paint, install a suitable crimp-on ring connector, and screw that puppy down with a nice stainless steel self tapping screw and call it a day. See, like I told you, it WAS a very easy fix after all. I'm probably a little off my rocker, but I like challenges like yours and would have spent alot of time and sweat tracing the root of the problem staring from the vehicle itself and working my way back to the trailer lights themselves.

 

[kamby]

Re: Need help re-wiring my trailer!

Like what the others said, scrape some paint, drill a hole in the frame and run a ground wire.

Another thing you could do to since it is a painted trailer and the lights appear to ground through the mounting studs run the ground wire all the way back from the point where you ground it to the trailer frame and attach the ground wire to the post on any lights you may have. This will get you a good known ground to the lights and still ground the trailer so you can use side marker lights as well.

 

[Biggems]

Re: Need help re-wiring my trailer!

Ok well it seems like we have the problem solved. But dont everybody get too excited just yet! lol

Here is what I am going to do since I dont have a drill. I'm going to attach the front ground wire to one of the bolts on the coupler at the tongue of the trailer. I'll also take off the bolts on the mounting brackets behind each tail light, sand off the paint, and re-bolt them on. Hopefully this will solve all my problems.

I do have a question about the side marker lights though...There is a single black wire coming from each side marker light that I spliced into the brown wires on each side. There is a single white ground wire coming out of each tail light that is grounded on the mounting bracket. When I turn on the lights, all the lights come on including the side marker lights and when I hit the breaks all the lights go out including the side maker lights. Do I need a seperate ground wire for the side markers? If so, how do I do that? should I splice another wire into the black wire coming from the side marker lights and attach that one to the frame somewhere?

 

[Rocky_Road]

Re: Need help re-wiring my trailer!

No...no...no!

Don't you dare touch the side markers! The black wire is your hot lead...ground that, and you will probably have half the posters here looking up your address...and loading their 12 guage!

I am officially 'swearing' off of this thread...and heading for an AA meeting.

 

[Biggems]

Re: Need help re-wiring my trailer!

haha ok ok I wont touch the black wire from the side marker lights. I'll just leave them as they are, spliced into the brown wire on each side.

I apologize if this has gotten frustrating for some of you. But I do appreciate you're help. I am a complete noob at this. But thanks to alot of you, I've already learned alot.

 

[NYBo]

Re: Need help re-wiring my trailer!

Your side markers are grounded through the mounting bolts. They will be fine once you ground the trailer frame properly.