2nd Gen Non-Engine/Transmission Trailer blowing fuses

[trqmnstr]

Hey guys,



I just bought a used 18ft car hauler and rewired the entire thing. It uses the 7-pin. Everything functions properly except when I turn on the running lights and then apply the brakes it blows the square green 40amp under the hood. I triple checked my wiring and all is well. There are no rubbed through wires and no two wires are touching. What's the deal. Thanks in advance. Clay

 

[bmoeller]

Are the bulbs good, on the trailer lights?

 

[trqmnstr]

I replaced the bulbs and blown fuses and it did the same thing. I used 14 gauge instead of the standard 16 gauge. Does that matter?

 

[TRAMPLINEMAN]

Have you tried hooking up to a different trailer? Maybe it's in the truck wiring.

 

[K5IP]

Aloha,

I'am not sure what your wiring is like, but in many installations (including my 95 ram) the brake switch provides a return connection to ground to complete the circuit.

It sounds like you have a wiring error, one that allows 12Vdc from the fuse to be shorted to ground through the brake switch.

When you check your wiring, try to look for a polarity reversal (switching the high and low side of the clearance lights) or some other switch that can make this happen.

If you stop and think about it I think about what you have done, I think it will become clear. Good luck, electrons are always fun!

Rog

 

[trqmnstr]

I have pulled a few other trailers with no problem. This is the first to cause a problem. Therefore, it must be the trailer. Any other suggestions? Thanks

 

[jeepit]

If this is a trailer with the box style lights that can be removed you may want to pull the lights and check to see bare wire is not contacting trailer. I had a wire wear behind the light so you could not see it until it was removed.

 

[Lordsman]

Mine did the same thing last time I hauled some equipment in my trailer. Something is wrong with the electric brakes or brake wiring on my trailer. I changed the fuse, and switched to a flat 4 connection I had on the truck so I could get where I was going, lights were fine, no shorts. That fuse under the hood is tied in w/ running lights and brakes. I haven't fixed mine yet though. It could have been the round 6 pin connector on my trailer as things didn't look too good inside there when I pulled it apart.

 

[BK]

Directionals work good? parking lights work good?



If all the lights are working ok, and it's just when you hit the brake it sounds as if there is a wiring problem at the brake controller.

The wire colors used in the dodge do not match up to the normal wire colors of the brake controllers. Check that wiring.

I also thought the 40amp under the hood was used for the B+ to charge the batteries that would be on board the trailer. That should have much todo with the brake controller.