Keep blowing fuse for brake/blinker lights

[bweldon]

I noticed while coming back from our last trip the blinkers and brake lights on the camper were not working. My owners manual for the truck (2011 F150) showed that fuse position #73 was for the TT blinkers and brakes. Sure enough I pulled it out and it was blown. I replaced it and I blew thru two more right away. Obviously my problem isn't the fuse, but what is it? Im not very seasoned with electrical so any help is much appreciated. What is causing the fuses to blow? Thanks.

Barry

[Drathaar]

Barry, assuming the fuse doesn't blow when the AS is disconnected, you've got a short to ground somewhere in your trailer.

I think I would start trouble shooting by looking over the 7 pin. Then by pulling the bulbs and looking things over for something obvious with bulb or socket. Then, with the bulbs out, use an Ohm meter and check from your male 7 pin plug brake light terminals to ground (the trailer frame or skin, or the ground terminal on the connector). You should not (my best guess) be able to read continuity to ground. If you do, that's the circuit that needs more investigation.

Hope that helps.

[cwbiii]

A short is one possibility... the other is that the trailer lights added to the vehicle lights on your tow vehicle equal more load than the fuse can handle.
This is quite common with incandescent bulbs. Several choices here...
1) a slightly larger fuse if the wiring will support it.

2) Switch to LEDS for as much of the trailer external lighting as possible.
A LED bulb uses about 20% of the power of an incandescent bulb.

3) Adding inline relays to a separate power panel for the trailer connector.
The relays put a small load (less than one bulb) into the circuit and can power up to their rated value... which is a rating on the relay and is available in different power ratings. This requires a relay for each separate lighting circuit... brakes, running, right turn, left turn. Make sure the turns work in concert with the ones on the vehicle as it is easy to make them the opposite but this could leave them ON on the trailer when they are OFF on the vehicle. Significant electrical wiring knowledge and skill required for this.

#2 & #3 can get expensive and be time consuming...
#1 is cheap if you don't overload the circuit and fry the wiring which will then be more expensive than #2 or #3 to fix. Not to mention smoke coming out from under the dash while you are driving down the street does not make for "Happy Camping".

Chuck