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

[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

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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.

"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.

 

[Scobysisters]

UPDATE: We removed the 6-pin connector on the toad (F150). It was really corroded, especially the wire for the Right Turn signal (the one giving us problems). We replaced that connector, cut all the wires down to try to remove the corrosion, and used some vinegar on the wires to remove corrosion. All the wires are now clean, except there still may be some corrosion that spread further down that Right Turn wire, but it's a lot better. We reconnected everything...but this did NOT solve the problem - darn it! So, now we're going to look at the tail light of the toad tomorrow.
Thanks EVERYONE for chiming in to try to help out. This is so frustrating to say the least.

 

[Scobysisters]

Handy tool to test trailer plugs

View attachment 21143

We do have a 7-pin and a 4-pin connector tester, but not a 6-pin tester. Need to get one, though. thanks

 

[Rollin Ollen]

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.

I'm not all that thrilled with the JK wrangler I have now. I call it a car in Jeep's clothing. I don't like plush carpet and a whole lot of electrical gadgets. I've had a CJ, XJ, TJ and now this. My absolute favorite was the TJ. It had 350,000 Kilometers on the clock and easily another 50,000 unregistered (towed). It first died on me about thirty miles west of Hawthorn Nevada on an old mining road. It did restart so we didn't have to walk back to civilization. It ended up needing a new crank position sensor. It was then deemed "no longer reliable" by my wife so it had to go. I still like the "go anywhere ya want" that the Jeep is famous for and it is so simple and easy to tow. I'm glad you like your F150 but it's too big for my liking. Different strokes.


Anyway, I sure hope your issue is with a diode and easily solved.

Darrell

 

[Wemustrv]

Have you put a test light the connector coming off the motor home to verify the turn signal if functioning at that point? next plug in harness from the truck and trace the right turn signal test is as well, next move towards the connection point to the actual truck harness and taillight assembly

 

[Scobysisters]

Have you put a test light the connector coming off the motor home to verify the turn signal if functioning at that point? next plug in harness from the truck and trace the right turn signal test is as well, next move towards the connection point to the actual truck harness and taillight assembly

We'll test the 7-pin MH connector. Last time that was checked was about a month ago, and all the wiring at that end were "hot". But, we'll check again with the tester we have. thanks

 

[rvkev]

It was really corroded

From your picture of your connector, it appears you have:

Tail / marker lights

Brake / right turn

Brake / left turn

Ground

I am guessing your toad brakes are in the hitch.

Take a picture and/or make a diagram. Remove the wires. Cut your wires back to shiny copper, or clean them with fine sand paper or steel wool. Be careful not to get steel wool fragments in the contacts. Solder the ends of the wires and use electrical contact grease to install the wires back into the correct holes. Consider buying a better grade metal connector assembly from a trailer dealer. Wrap the wire assembly with good electrical tape, preferably 3M. Do not over wrap so the wires will not go back in the socket.

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I suspect your poor contacts have made other contact areas to become compromised. Now you have a start and you did not pay Freightliner to search for the problem. You can use electrical contact grease on the light socket connections if you like.

 

[Rollin Ollen]

From your picture of your connector, it appears you have:

Tail / marker lights

Brake / right turn

Brake / left turn

Ground

I am guessing your toad brakes are in the hitch.

Take a picture and/or make a diagram. Remove the wires. Cut your wires back to shiny copper, or clean them with fine sand paper or steel wool. Be careful not to get steel wool fragments in the contacts. Solder the ends of the wires and use electrical contact grease to install the wires back into the correct holes. Consider buying a better grade metal connector assembly from a trailer dealer. Wrap the wire assembly with good electrical tape, preferably 3M. Do not over wrap so the wires will not go back in the socket.

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I suspect your poor contacts have made other contact areas to become compromised. Now you have a start and you did not pay Freightliner to search for the problem. You can use electrical contact grease on the light socket connections if you like.

I'm glad to see you added "apply solder to the ends of the wire". It is such an easy way to make sure there are no "stragglers ( threads of wire that don't go into the socket), less chance of corrosion and better contact with the socket.. I always apply contact grease as well. Good advice. thanks for sharing.

Darrell

 

[rvkev]

"apply solder to the ends of the wire"

Darrel, Thank you for the clarification to our members. I know what I meant and so did you. The procedure is tinning the ends of the wires. The little screws are easy to strip out. Be careful not to over tighten.

 

[Chargerman]

Have you testing the plug with a volt meter with the blinker on? If That is good then plug in the umbilical and test at the other end of it. Has this already been done? No sense checking the taillight until you know that you are getting voltage through the umbilical.

 

[Scobysisters]

UPDATE: we did clean the wires for the 6-pin connector and reconnected those wires. But, we haven’t soldered the ends - will do that as well.
HOWEVER, I JUST put a 7-pin Tester on the 7-pin connector on the MH - something I should have done FIRST. Well, that tester shows the same issue as the Toad’s Rt Blinker - The Rt Turn light on the Tester also lights up and STAYS solid - doesn’t blink.
SOooooo….I think it’s probably a wiring issue at the Motorhome. Darn