7pin wiring problem. Please help!

or you could use the rv battery as well to run the lights, then you only need a wire from the positive post of the battery, maybe an idea to have a fuse inline just in case you hit the ground pin, maybe also an idea to check the one light bulb as well, as i have see a bulb filament break and short to the other filament...

mike-s wrote:

Djsrcy wrote:
okay. When the wife gets home I will use her battery and a couple wires.
So I will connect a wire from her car's negative post to a known ground on the CAMPER and then connect a wire from her car's positive post and touch each wire on the 7 pin. correct?

That will work, until you connect the positive wire to the ground on the 7 pin and make sparks fly.

That’s why I suggested briefly touching the wire. ;)

Actually, doing this at the junction block under the trailer is a better idea so if you do a little accidental welding there’s no damage to the connector. Then just match the colors from there to the connector.

Djsrcy wrote:
okay. When the wife gets home I will use her battery and a couple wires.
So I will connect a wire from her car's negative post to a known ground on the CAMPER and then connect a wire from her car's positive post and touch each wire on the 7 pin. correct?

That will work, until you connect the positive wire to the ground on the 7 pin and make sparks fly.

drsteve wrote:

Djsrcy wrote:
okay. When the wife gets home I will use her battery and a couple wires.
So I will connect a wire from her car's negative post to a known ground on the CAMPER and then connect a wire from her car's positive post and touch each wire on the 7 pin. correct?

That is what I would do at this point, to ensure that the problem is not a miswired trailer plug. Remember not to touch the 12v to the ground pin in the connector.

While I agree with YC-1's post above, I think you are better off starting with drsteve's post about testing each wire one at a time.

Definitelygrab a notepad and make a map of what each wire position on your tow vehicle controls. Make sure you write down each blade position, do not rely on any pre-printed diagram. Then ask your wife to stand behind the trailer and call out lights as you test each pin on the trailer. Write down each wire position from the trailer and I bet you'll find that the trailer plug is miswired.

a few tips.

She can tell the difference between a taillight and a brake light because the tail lights will also light up all the side and top marker lights.

When the side and top marker lights go on, the two tail lights should be the same brightness. If one tail light is considerably brighter that the other you most likely have the bulb installed 180 degrees in the brighter bulb socket.

If you have any lights that just will not turn on, or one is brighter than the other, then go back and follow YC-1's testing.

You are trying to fix too many problems at the same time. You will just get confused.

Go back to the left tail light. Turn on the tow vehicle running light. If your test light comes on by touching the socket pin or the wire going into the bulb while using the long wire as suggested as a ground then you have power that far back to that light. Forget the right side for now.

Then put the test light on the other wires of the bulb/socket. IF the test light comes on when touching what seems to be both sides of the bulb then your ground is missing for that bulb.

Remove the bulb, use your test light to find which wire lights up the test light. Put the bulb back in and then use a needle to pierce the wire that did NOT light up the test light. Connect your temporary ground wire there and the bulb should light up. If there are more than one wire that is ok. Probably one is the turn signal.Just pierce the ones that did NOT light up the test light.

Ok, once that simple circuit is diagnosed you can start working on the left turn signal. It is usually just the other wire and should flash your test light when touched.

If these simple tests fail you have a problem between the socket and pigtail. I think you can sort it quickly if you break it down to a couple of basic tests.

If you use a substitute battery you may chase your tail, lights that is.

What you are doing is substituting a

Djsrcy wrote:
okay. When the wife gets home I will use her battery and a couple wires.
So I will connect a wire from her car's negative post to a known ground on the CAMPER and then connect a wire from her car's positive post and touch each wire on the 7 pin. correct?

That is what I would do at this point, to ensure that the problem is not a miswired trailer plug. Remember not to touch the 12v to the ground pin in the connector.

You will need either a planned diagnostic procedure or a trailer tech with that in memory.
Here's how I would proceed if you rolled into my garage: Using the towing vehicle, test all connections at the trailer cable's umbilical scket with either a meter or a light. *Sometimes, a frayed wire inside a wire jacket will cause intermittents so I shake the wires going to the socket while I test.*
If truck wiring is good, I check power wire and ground continuity to all the bulb sockets from the trailer umbilical (you can power them and use your light but that won't check for bad grounds). Check resistance of bulbs for continuity across the filaments. If all checks good, I spray the bulb sockets with an electronic spray (Caig brand-Deoxit), replace bulbs, and check systems. If any bulbs refuse to light, I will go back and troubleshoot that ciruit, starting at the bulb holder.

You stated that you don't have a battery and that one ground wire was left disconnected. I would connect that wire to the frame. Even if you are sure it is meant for the battery (-) polarity, it won't hurt anything to connect it. BTW, you will need a battery to tow, I'm sure you know that.

okay. When the wife gets home I will use her battery and a couple wires.
So I will connect a wire from her car's negative post to a known ground on the CAMPER and then connect a wire from her car's positive post and touch each wire on the 7 pin. correct?

wnjj wrote:

drsteve wrote:

Djsrcy wrote:
Thank you guys!
The plug is not molded. I just replaced it. It matches the tow vehicle. I am on my way to get the light tester and will make sure I have a good ground. It is an 04 timber lodge 26RLS. Also, my truck display says “trailer wiring fault”
I’ll let you know how it goes,
Thanks again

I'm beginning to suspect the previous owner may have the trailer wired so it worked with his own miswired truck...

I agree. It sounds like the right turn is connected to the running lights, among other things.

Don’t assume anything about wire colors. Though the 7-way diagrams tend to show “standard” colors, all bets are off with trailer manufacturers. You need to get an external source of 12V and connect the negative to the known ground and then briefly touch the positive to each of the other wires one by one and see what lights up and listen for the brakes.

You can do this at the trailer plug or junction box.

What he said. Your truck says the trailer wiring is at fault, and it sure sounds like it is. Apply 12v to each wire one at a time at the trailer connector, and see what happens.

Deleted