Right turn signal constant on tow connection

Hello all

So getting the boat ready to go out and hooked the connection to my truck but the turn signals on the truck stop working with the trailer connected. Come to find that there is constant power at the right turn signal pin on the connector from the truck. Brake lights and markers work fine. Soon as I use a turn signal it stops working on my truck until I disconnect the trailer. Btw Trailer is completely rewired all new lights and such. But the issue is on the truck side connection

 

Sounds like the trailer might be wired wrong.

 

$9 CXTM 7 Way Trailer Plug Tester, 7 Pin Trailer Light Tester with LED Lights 7 Way RV Connector Wiring Tester for Truck, Plug & Play

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8 buck for a 7-pin tester. Or probe the connector to test, the turn signal should be the pin at the 3 o'clock and 9 o'clock positions.

I'm inclined to think it is the trailer wiring as well- have you tried plugging the trailer into another truck to test?

 

I thought so hence why I rewired the whole trailer. What I found after it still didnt work right was the right turn signal pin coming from the truck has constant power.

 

Did you check the left turn signal to see if it had power all the time also. If you have a constant power for the right turn signal at the plug then your right turn signal should be on solid. Unless Toyota uses a ground system to control the circuit.

 

I think the pin directly across from the RT always has power.
Is it possible the connector has been altered, or your trailer is backwards?

 

I would unplug the 7way connector on the truck and test the pins at the connector to the plug and see if you still have constant power at that pin.

 

Are you using the 7-pin or the 4-pin? If you turn on the blinker of the truck, does the power start to pulse or still stay on? What wires are you probing to check for turn signals?

 

7 pin uses the same pin for brake and turn.

 

Tested the left turn signal at the truck side connector and its working as intended only when the left blinker is on.

Checked both 7 pin and 4 pin. Right turn is constant on both.

Inspected both connections and they look original with toyota logos on the trailer output connectors.

 

Wondering if one of the relays is stuck or shorted open its only affecting the trailer connector. So when I plug the trailer up it backfeeds and kills my truck turn signals. Guess I can check all the trailer related relays under the hood for being open.

Will also disconnect the 7 and 4 pin since its doing it on both maybe a ground issue

 

If there is constant hot to the pin without the trailer connected, you have a wiring problem. Stock tail lights?

 

Yes still stock

 

I would check to see if the 12V constant is shorting out to the turn signal wire.

 

It sounds like it might be shorted in the 7 way to 4 way. If you checked the plug that goes into it and it works right and then you plug it back into the 7way it gets power to the turn signal constant

 

Pull your TOWING Fuse (25A) and see if the power goes away at the trailer connector, if it does then the issue is most likely the Combination Meter (Instrument Cluster).

For some reason Toyota chose to have the Meter run the trailer lights on the 3rd and 4th gen trucks and a short in the trailer will wreck the circuit in it.
I would advise anyone with a 3rd gen to replace the TOWING fuse with a 10 or 15 amp so it will hopefully blow the fuse instead of fry the Meter if a trailer short occurs.

 

I appreciate everyones input I will check the connector and pull the fuze and check it tomorrow!

 

I hope that works for you.

 

So yeah still power with towing fuse out.

 

Try unplugging the headlight multifunction switch and then check to see if you still have constant power.