Trailer Lights run amuck

[6gun]

Ok, this is bizzare.... just towed boat 1600 miles with no issue at all (except fuel burn...ugh). Truck and trailer lights worked perfectly. Disconnected boat to clean and shine... reconnected and no brake or turn lights. Lights on truck work fine. Running lights fine on truck/boat fine. Checked plug voltage with Flashers on, no voltage on R and L pin or round plugs when flashers are on. Ok, need to check connection on plug on the top of the spare tire as symptoms point to connection...however, before I dig into it, wondered if anyone else has had this issue and simple fix. Fuses check fine, but only found R and L turn fuses. Someone in an earlier post makes reference to a relay left in the glove box...?? More info on that requested. Thanks in advance.

 

[Hockster]

Ok, this is bizzare.... just towed boat 1600 miles with no issue at all (except fuel burn...ugh). Truck and trailer lights worked perfectly. Disconnected boat to clean and shine... reconnected and no brake or turn lights. Lights on truck work fine. Running lights fine on truck/boat fine. Checked plug voltage with Flashers on, no voltage on R and L pin or round plugs when flashers are on. Ok, need to check connection on plug on the top of the spare tire as symptoms point to connection...however, before I dig into it, wondered if anyone else has had this issue and simple fix. Fuses check fine, but only found R and L turn fuses. Someone in an earlier post makes reference to a relay left in the glove box...?? More info on that requested. Thanks in advance.

You didnt remove the plug or replace it with the lights still on? That surge will pop the fuses...

 

[Squatting Dog]

Which trailer plug were you using?

7 pin or 4 pin

Yes, there is a reason.. The 7 pin trailer plug requires extra fuse and relay to power +12 vdc pin.

4 pin trailer plug does not require relay/fuse

I would check again, it sounds like load surge popped fuse..

-Greg

 

[6gun]

Well.... hell ya i did ******** that i yam.. BINGO!! Stop Turn Relay Power cartridge Fuse #73 toasted. THANKS MAN!!

---------- Post added at 09:43 PM ---------- Previous post was at 09:42 PM ----------

Which trailer plug were you using?

7 pin or 4 pin

Yes, there is a reason.. The 7 pin trailer plug requires extra fuse and relay to power +12 vdc pin.

4 pin trailer plug does not require relay/fuse

I would check again, it sounds like load surge popped fuse..

-Greg

I always have used the 4 pin. No brakes or aux power to trailer. Thanks again gents.

 

[Yukon Joe]

So what did you do? Plugged the trailer in with the truck lights on?

Joe

 

[6gun]

Zackly. As i recall, truck was running, it was dark, went and plugged trailer lights in, running lights on trailer came on, no turn signals or stops. Note to self: truck must be all dark, then plug trailer in.