20 amp turn signal fuse blown in 1998 F150 truck

[jayfeather421]

It appears that if I hook up the 7 pin connector with the truck running it
blows the 20 amp fuse for my turn signals. Should the truck ignition be
off when hooking up?

[RedHorse1]

Wouldn't think so.
I'd bet a short is causing the fuse to blow. Start with the TT lights. Remove the bulbs and use an ohm meter to check for a wiring short. I'll bet it's a bad bulb or wiring damage.
New trailer or new to you trailer? Has the '98 truck pulled another trailer with lights before?

[jayfeather421]

Yes , it has pulled before. Since I had replace all the bulbs already , I think I should just get it checked out for short.

Thanks

[bayleightucker]

have seen this question somewhere here before, i believe the consensus was to shut off the tv while hooking up, i have always shut mine off and have had no problem, but there are many here wiser than i, hang on, you will get some good advise. happy camping

[tinlizzie23]

Definitely sounds like a short in the trailer wiring. Shouldn't matter whether TV is running or not, but make sure the lights are off when hooking up, so you don't throw a large sudden current spike on the fuse. With no current on the trailer wiring (not connected TV), remove a bulb and check with a continuity meter whether or not the hot terminal in base of socket is connected to ground. If so, either that individual hot wire is rubbing a ground somewhere, or perhaps your main turn sig wire in the 7-way is grounded. Either way, you will have to go through the system and find the short to fix the problem.

[Gma-n-Gpa]

Jayfeather - may be a silly question but --- does the fuse blow if you have the TV off and connect the TT? Does the fuse blow when you connect this way and then use your turn signals? In my opinion - if you can connect with TV off and don't blow a fuse and if connecting that way your lights work as normal (no fuse blow) then it is not a short. Just thinkin'