Blown fuse

[toastie]

Just got back from a great fishing trip at Fletcher Pond in Hillman Michigan. Went to hook-up to go home and had problems with my power tongue jack, it stop, then it started back up, hook-up, than came home. When I went to un-hook at home, it work, than stop, and would not work again. Checked my battery and it showed fully charged, but the 30 amp fuse between the battery and the distribution box was blown. My electrical system has working great all summer until today, and my question is, what caused the blown fuse?

Thanks

[Condoluminum]

Toastie-

I'll try to keep thread alive until electrical wizards weigh in...

To blow the 30A fuse, there would have to be either a short (bare wire in contact with ground or metal surface), or very heavy load in either the jack or something like Air Conditioner... Since you didn't mention A/C use, and no body damage or shaking severe enough to cause bare wiring short, I'd guess problem in power switch or motor of the jack... If the motor bearing or transmission starts to fail, the friction load goes up, wiring gets hot, insulation might get compromised, and the load increases until a fuse could blow... Might be possible to test jack alone with no trailer load by using another jack to raise front of trailer and seeing if electric jack will smoothly move up and down with no load, or struggles. Struggle indicates failing jack or component of jack...

[Anon]

The problems at hook-up before you made it home make me suspect that it is the jack.
Do what was suggested and see if the jack moves freely with no load on it. Also listen for any abnormal sounds coming from the jack while running it up and down.
I had a similar problem back a few years. My Argosy 24 jack must have leaked water into it and needed grease BADLY. It actually bound up on me and I had to tear into it to get it all lubed. It blew the fuse too.

[Lumatic]

Just in case I have a manual crank to operate the electric jack. Getting stuck with the jack down and no juice aint no fun. If you are not familiar with the crank you just take off the electric jack cover plate and it fits right in.

[toastie]

Originally Posted by Condoluminum

Toastie-

I'll try to keep thread alive until electrical wizards weigh in...

To blow the 30A fuse, there would have to be either a short (bare wire in contact with ground or metal surface), or very heavy load in either the jack or something like Air Conditioner... Since you didn't mention A/C use, and no body damage or shaking severe enough to cause bare wiring short, I'd guess problem in power switch or motor of the jack... If the motor bearing or transmission starts to fail, the friction load goes up, wiring gets hot, insulation might get compromised, and the load increases until a fuse could blow... Might be possible to test jack alone with no trailer load by using another jack to raise front of trailer and seeing if electric jack will smoothly move up and down with no load, or struggles. Struggle indicates failing jack or component of jack...

The fues that blew was the fuse from the battery to the distribution box. I also have a inline fuse from the electric jack on the outside and it was ok, the electric tongue jack is only 5 months.

[Aerowood]

What Is the amprage of the fuse between the jack and source? Do you have a breakaway switch the could be tripped on or any other DC circut that draws a high load on?

[toastie]

Originally Posted by Aerowood

What Is the amprage of the fuse between the jack and source? Do you have a breakaway switch the could be tripped on or any other DC circut that draws a high load on?

Amperage between the source and the jack is 30A, from the in-line fuse there is a wire that is wrapped around a cluster of wires, and those wires are the breakaway wires and the black wires of the bargman 7 pin which would be the battery charge between the trailer and the TV. Wouldn't it be better to run one wire direct from the positive side of the trailer battery to in in line fuse of the electric jack?...............thanks

[toastie]

Originally Posted by Condoluminum

Toastie-

I'll try to keep thread alive until electrical wizards weigh in...

To blow the 30A fuse, there would have to be either a short (bare wire in contact with ground or metal surface), or very heavy load in either the jack or something like Air Conditioner... Since you didn't mention A/C use, and no body damage or shaking severe enough to cause bare wiring short, I'd guess problem in power switch or motor of the jack... If the motor bearing or transmission starts to fail, the friction load goes up, wiring gets hot, insulation might get compromised, and the load increases until a fuse could blow... Might be possible to test jack alone with no trailer load by using another jack to raise front of trailer and seeing if electric jack will smoothly move up and down with no load, or struggles. Struggle indicates failing jack or component of jack...

Maybe this is my problem.

Chinese-Made Auto Fuses May Cause Fire