No turn signals on M416 all else works (1 Viewer)

[mep1811]

I have a trailer (M416) lights issue and am at a loss how to resolve it.

When hooked up to my FJ-60, 7blade RV to a 4 pin trailer using an adapter I do not get any turn signals.

When the trailer is hooked up to another vehicle, 4pin to 4 pin the trailer lights work perfectly.

When my FJ-60 is hooked up to a different trailer , 7 blade RV to 7 Blade RV, the trailer lights work perfectly .

When hooked up the FJ-60, I have tried three adapters with no luck. The harness is new on the trailer.

I had a 7 blade RV plug but rewired it with a 4 pin.

The trailer lights never really worked right but in troubling shooting this, there were two bad vehicle

grounds. I changed the trailer harness because the old harness was beat up and patched in places.

The only thing I can think of is to change the trailer harness back to a 7 blade RV .

Any suggestions ? Thanks in advance.

 

[Living in the Past]

If your brake lights work the problem is in the vehicles wiring since brake and turn signals share the same element in the bulb and wiring all the way back to the plug on the four pin plug. My 04 4Runner has the factory seven pin plug and using the standard seven pin to four converter the lights on my M416 work fine.

 

[mep1811]

Thanks . The FJ-60, when connected to a different trailer , via a 7 blade RV plug , works just fine. All the trailer lights work.

 

[mep1811]

I decided to have the truck side wiring harness removed and a new 4 pin harness installed. I took my truck to U-Haul so they would be on the hook if things did not work. While I was there, I saw this module that powered the trailer lights off the vehicles battery and not the vehicle harness. The guy at U-Haul said that some older vehicles have weak electric systems that can't fully power trailer lights.

Everything works perfectly now.

https://www.uhaul.com/MovingSupplies...odule?id=13612

 

[Living in the Past]

I decided to have the truck side wiring harness removed and a new 4 pin harness installed. I took my truck to U-Haul so they would be on the hook if things did not work. While I was there, I saw this module that powered the trailer lights off the vehicles battery and not the vehicle harness. The guy at U-Haul said that some older vehicles have weak electric systems that can't fully power trailer lights.

Everything works perfectly now.

https://www.uhaul.com/MovingSupplies...odule?id=13612

View attachment 1384221

I have a feeling the issue was in the seven pin plug. Installing that plug is a good idea. Want to do that to a number of my vehicles including my 99 4Runner with the port installed trailer hitch and wiring. Was shortly after that Toyota switches to the modern style where the trailer lights are on they own fuse. My 1970 FJ40 the flasher is so weak it would work with the one extra bulb on the turn signals. Thought of just switching to a LED bulb but these protects the vehicle wiring from any shorts or grounds in the trailer wiring.

Glad you got it working.

 

[NMC_EXP]

If the tow vehicle has separate tail and turn signal lights, a special wiring kit is needed. It includes a box to sort out the signals.

Found this out the hard way when I put a 4-pin hook up on my 89 Toyota truck. A simple 'T' plug in harness would not work.