No brake lights or turn signals on trailer

[TedN]

Truck is a 2022 1500 Big Horn level 1, factory tow package including brake control
Here's the backstory.....
Got a used trailer at an auction. The trailer has brakes and the normal running lights. All the existing lights were broken, so got a set of LED lights. The previous owner also cut the 7 pin cable and spliced in a 4 way flat plug. Wired the new lights to the existing color coded wires and cut off the 4 way plug.
Using the cut wires at the plug end, tested the individual lights with a battery. They all worked when jumping to the battery. Wired up a new 7 way plug following the "guide" on the truck plug cover. Thought I was good to go...... NOPE!

The marker/running lights come on with the lights on the truck, the trailer brakes work and the controller recognizes the trailer. BUT, no trailer brake lights or turn signals.

I did notice that when I checked the truck side plug, there was no "intermittent" power on the left or right turn signal tabs. All connections appear to be good on the truck side plug. I know the 4 way flat plug works as it should on my small utility trailer. I am at a loss....

Any suggestions on where to start looking? The truck turn signals and brake lights work, so not a fuse....

 

[bigdodge]

Truck is a 2022 1500 Big Horn level 1, factory tow package including brake control
Here's the backstory.....
Got a used trailer at an auction. The trailer has brakes and the normal running lights. All the existing lights were broken, so got a set of LED lights. The previous owner also cut the 7 pin cable and spliced in a 4 way flat plug. Wired the new lights to the existing color coded wires and cut off the 4 way plug.
Using the cut wires at the plug end, tested the individual lights with a battery. They all worked when jumping to the battery. Wired up a new 7 way plug following the "guide" on the truck plug cover. Thought I was good to go...... NOPE!

The marker/running lights come on with the lights on the truck, the trailer brakes work and the controller recognizes the trailer. BUT, no trailer brake lights or turn signals.

I did notice that when I checked the truck side plug, there was no "intermittent" power on the left or right turn signal tabs. All connections appear to be good on the truck side plug. I know the 4 way flat plug works as it should on my small utility trailer. I am at a loss....

Any suggestions on where to start looking? The truck turn signals and brake lights work, so not a fuse....

take the trailer plug back off and touch each wire to the truck outlet so you will have the correct order

 

[TedN]

take the trailer plug back off and touch each wire to the truck outlet so you will have the correct order

They are definitely wired correctly (meaning function). I don't think there is power going to the truck plug on the turn signal prongs.
I would think that using a voltage tester on the turn signal prongs (and ground) should provide an intermittent voltage spike (0 then 12, 0 then 12, etc...) while the trucks signals are operating.
I did not get ANY voltage from either the left or right prongs. Don't get any voltage from them with the hazard flashers either.

 

[Richard320]

Check the connection on the back side of the 7way.

 

[CHeYeNNe71]

For free, I would disconnect battery for a good hour to reset all systems and go from there. The canbus system is finicky from what I've seen. It's free and worth a shot. Don't freak out if everything doesn't come back right away, can take overnight I've seen.

 

[TedN]

Issue solved! (at least for now). This truck was purchased used about 2 months ago. Apparently, the previous owner must have connected something that shorted and blew both "trailer turn signal" fuses. They were F09 and F10, 20 amp micro fuses. Replaced them and have full functionality.

Thanks for the suggestions.