Towed vehicle turn signal not blinking when connected to MH in Tow Mode

[rvkev]

There is no ignorance here

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Everyone cannot understand everything.

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If the problem only happens when in tow mode attached to the coach, then the coach flasher(s) may be the problem.

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If the right light is not flashing when disconnected from the coach but in tow mode, the problem may be in the towed vehicle’s flasher or even the tow mode components.

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You certainly have a puzzle.

 

[Joe Hogan]

IMHO, Best is to find the OEM schematic of the circuit in question and trace it back from the bulb with a test light. FMCO has all these circuits nicely diagramed in Service Manuals.

another way to isolate the issue is to apply 12v to the appropriate circuit at the front bumper to see if the problem is truck

 

[Joe Hogan]

Handy tool to test trailer plugs

 

[Rollin Ollen]

Where is the Tow Wiring Harness? Is this behind the 6-pin connector on the toad? Or at the MH end? Is this something we can get to? Or is this something an electrician/tech should do? And if so, an RV tech or a trailer tech, or a Blue Ox tech? Who would know more about this issue? We’ve asked RV techs and they said it may be the Tow Relay on the MH - it’s not because we replaced that relay. It’s also not the fuse. Thanks for your reply.

On My Jeep, I have a "non factory" wiring harness that connects to the Trailer Wiring Socket on the Coach. That harness runs underneath the Jeep to the FACTORY plug at the Left Tail Lamp. It does not use any diodes. All it powers is the Park Lamp circuit and the Left and Right Turn Signal circuits. The Brake and Four Ways use the same circuits. It is a very simple set up and does not use any OEM power from the Jeep.

It sounds like your set up uses some factory circuitry on your F150. If that's the case, I suspect you have a sophisticated Ford problem. Is it too late to buy a Jeep? Just kidding!!
Good luck and let us know how your problem was resolved.

Darrell

 

[rvkev]

What do you mean by “connector is hooked up, but the hitch is not connected?

The wiring system is plugged in. The coach is not physically attached to the tow vehicle. Try in tow mode and not in tow mode. I suspect there is a ground feeding back thru the hitch. Process of elimination.

 

[John&Andrea]

Some use a diode kit on the tail lights on the towed vehicle. It allows two lines in on one circuit or bulb. I think I said that right. If you are using the tail lights on the towed vehicle there may be diodes used.
I don’t use them. I have small LEDs under my tail lights.

 

[John&Andrea]

Tail Light Isolating Diode System with Wiring Harness Hopkins Tow Bar Wiring 38955

Allows motorhome or R.V. to power the lights on the towed vehicle without power feedback. Great Prices for the best tow bar wiring from Hopkins. Tail

www.etrailer.com

 

[Scobysisters]

There is no ignorance here

---

Everyone cannot understand everything.

---

If the problem only happens when in tow mode attached to the coach, then the coach flasher(s) may be the problem.

---

If the right light is not flashing when disconnected from the coach but in tow mode, the problem may be in the towed vehicle’s flasher or even the tow mode components.

---

You certainly have a puzzle.

"If the problem only happens when in tow mode attached to the coach, then the coach flasher(s) may be the problem." THAT is the ONLY scenario in which that Rt turn signal on the towed vehicle doesn't flash. The MH flashers work fine when attached to the toad vehicle. So how can this be the coach's flasher malfunction?

 

[Scobysisters]

The wiring system is plugged in. The coach is not physically attached to the tow vehicle. Try in tow mode and not in tow mode. I suspect there is a ground feeding back thru the hitch. Process of elimination.

We're going to remove the tail light assembly of the toad vehicle tomorrow to look at that wiring. I think we have a diode kit installed in there, from reading more about this. So, we'll see what we can see in there.

 

[Scobysisters]

On My Jeep, I have a "non factory" wiring harness that connects to the Trailer Wiring Socket on the Coach. That harness runs underneath the Jeep to the FACTORY plug at the Left Tail Lamp. It does not use any diodes. All it powers is the Park Lamp circuit and the Left and Right Turn Signal circuits. The Brake and Four Ways use the same circuits. It is a very simple set up and does not use any OEM power from the Jeep.

It sounds like your set up uses some factory circuitry on your F150. If that's the case, I suspect you have a sophisticated Ford problem. Is it too late to buy a Jeep? Just kidding!!
Good luck and let us know how your problem was resolved.

Darrell

Haha - we USED to have a Jeep Wrangler as the toad (but hated that jeep) and needed more room (the F150 is our "garage", since we're full-timers). I suspect we have a diode system. We're going to remove the toad's tail light assembly tomorrow as see if we can notice anything amiss.