Main Trailer Fuse

[JohnG4706]

I have a Puma 23FB TT. I use a 30 Amp cord to hook my TT upto. Recently I shorted the umbilical card between my SUV and my TT. CW found the problem and when they replaced the Main Trailer Fuse under the front end, just back from the battery, they replaced it with a "Tow Ready 40 Amp Circuit Breaker." They gave me the package the circuit breaker came in and the blown fuse they removed.

I'm without power again. I just hooked up a Battery Tender solar panel to keep my battery charged while in storage. Having the package I went and bought a 40 Amp fuse at Advance Auto Parts.

Here's my question: On the side of the original blown fuse shows "12V X41 50A". On the side of the new fuse shows "12V X30 40A". Was the original main fuse a 50 Amp fuse? Could CW replacing it with a 40 Amp Circuit Breaker be my current problem in that it should be a 50 Amp Circuit Breaker?

I'm confused. Thanks.

[Old-Biscuit]

Fulltimer50 wrote:
The confusion may come from the produce description. Do a google on "Tow ready 40 amp circuit breaker" you will see what it is.

Would that be lettuce or celery :B


In-line 40A CB



OP.....
If the old 50A tested Good as you stated have you tested the replacement for 12V DC on both terminals.
If 12V DC on both terminals the issue is farther down circuit.

With converter AC input turned OFF (circuit breaker opened or AC power unplugged) test for 12V at converter battery cable connections.

No 12V at converter then check converter 'reverse polarity' fuses (Large 30a-40A fuses on converter)
If blown.......check that battery cables are correctly hooked up
OR if you blew them connecting solar


Simple circuit

Battery.....positive cable goes to 'in-line fuse or CB' then thru 'reverse polarity fuses' then to converter distribution and out to individual fused circuits.
Battery....negative cable to frame /ground

[mkirsch]

Okay, let's take a step back and get a clear picture of what happened. Everybody's confused.

Did you:

1. Install the "battery tender solar panel," then
2. Lose power.

OR

1. Lose power, then
2. Install the "battery tender solar panel"

How, exactly did you "short the umbilical between the TT and TV?" Did CW fix this or just replace the circuit breaker?

[westend]

There is no clear story here as to number and types of batteries, if the new fuse was for a newly bought solar panel, what that is, and any involved circuitry in the OP's RV.
If everything is tested good (and I don't know how you do that without a light or meter), the main suspect for no power would be the battery.

[Fulltimer50]

The confusion may come from the produce description. Do a google on "Tow ready 40 amp circuit breaker" you will see what it is.

[RJsfishin]

Quote:
I tested the "blown" fuse/circuit breaker
--------------------------------------------------
Well which is it ????
Your posting is so confusing:(

[LarryJM]

JohnG4706 wrote:
Larry, thanks. Do you have to do anything to have the circuit breaker reset? When I left CW, my power had been restored. The tech gave me the original "fuse" and told me it was "blown" and needed to be replaced.

I "assumed" since he had the electrical tools that he was correct. After sending my original post, I tested the "blown" fuse/circuit breaker and it was now GOOD. Now I'm really confused.

What would cause all the lights and other 12V appliances to not work? I tested all circuit breakers and plug-in fuses and all tested good.

Thanks again.

John

You could google and look it up, but I seem to remember reading that it's like a temp/time sort of thing for the auto resetting and some where in the back of my head I think it resets in under like a min. On the rarer manual ones I think there is a button somewhere to reset them, but I've never physically seen one of them so I'm not sure how they are reset. I have two under my trailer near the battery, one for the main power and one for the slide out.

With all that said, they can burn out, arc and get destroyed by weather so they can go bad, but that should take some time or be visibly noticeable.

I think they might be required just like fuzable links in a normal vehicle as protection on any battery to prevent extremely high amerage shorts that could cause a fire, etc. That's why they are so close to the battery. Normally a fuzable link is connected directly to the battery as the first layer of protection.

Larry

[JohnG4706]

Larry, thanks. Do you have to do anything to have the circuit breaker reset? When I left CW, my power had been restored. The tech gave me the original "fuse" and told me it was "blown" and needed to be replaced.

I "assumed" since he had the electrical tools that he was correct. After sending my original post, I tested the "blown" fuse/circuit breaker and it was now GOOD. Now I'm really confused.

What would cause all the lights and other 12V appliances to not work? I tested all circuit breakers and plug-in fuses and all tested good.

Thanks again.

John

[LarryJM]

JohnG4706 wrote:
I have a Puma 23FB TT. I use a 30 Amp cord to hook my TT upto. Recently I shorted the umbilical card between my SUV and my TT. CW found the problem and when they replaced the Main Trailer Fuse under the front end, just back from the battery, they replaced it with a "Tow Ready 40 Amp Circuit Breaker." They gave me the package the circuit breaker came in and the blown fuse they removed.

I'm without power again. I just hooked up a Battery Tender solar panel to keep my battery charged while in storage. Having the package I went and bought a 40 Amp fuse at Advance Auto Parts.

Here's my question: On the side of the original blown fuse shows "12V X41 50A". On the side of the new fuse shows "12V X30 40A". Was the original main fuse a 50 Amp fuse? Could CW replacing it with a 40 Amp Circuit Breaker be my current problem in that it should be a 50 Amp Circuit Breaker?

I'm confused. Thanks.

You appear to have FUZES confused with CIRCUIT BREAKERS. If the one CW originally replaced physically looks like the one they installed you never had fuzes only circuit breakers. In fact I would be extremely surprised if any trailer would use an actual fuze for what you are describing, but stranger things have happened. What AFAIK that is normally used is a self resetting CB which should not normally need to be replaced unless it tests bad.

Yes the original appears to have been 50A so CW replaced it with an undersized replacement HOWEVER ....

1. A 40A should be plenty and even a 30A would probably work.

2. CW and now you should not need to replace those and there are two types either self resetting or manual reset both of which don't have to be replaced if tripped just like a normal CB. I would recommend using the self resetting type which IIRC are the ones normally found at both RV and Auto Parts stores.

Larry