15 amp fuse keeps blowing when hooked to generator

[H4X0R]

I have a 2014 Keystone Fireside 26t, when I plug it in to generator it blows a 15 amp fuse in the TT that controls the use of the 12v battery. I checked the wiring (white neg, black pos) and it is and has always been connected correctly. After it blows I unplug the generator disconnect the negative from battery and put a new fuse in. After I put the new fuse in I connect negative back in and lights, water pump work fine off the battery alone, battery is 3/4 charged. But after doing so I turn off all lights, pumps etc... And turn back on generator. I let it stay on for about 2-3 minutes then plug in the 30 TT power cord. By the time I get back inside the TT the fuse has blown again? If anyone has any tips or solutions to my problem I would really appreciate it!

[H4X0R]

Ok on way home I say a keystone fireside just like mine and I knocked in the door to the house in which drive way it was parked in. I told the owner about my problem and he laughed at/with me and opened up his TT. Inside was 15a fuses from slots 1-4 and 30a on 5 and 6 and 40a on 7.... Thanks guys you all were correct. It's funny how u all know more than some off the salesman, dealers and techs! I asked him if it came that way and he said yes and showed me the converter manual and it says no more than 20a on 1-4 and no more than 30a on 5 and 6 and 40a on 7 for reverse battery hook up..... So I will be on the way to an auto store in the morning and plan a trip next weekend. Again thanks..

[H4X0R]

I did call the dealer, they said the manual will be sent to me with my trailer plates in the mail since the dealer is in Houston, tx and I live 4 hours away. I asked the dealer the question about the fuses which referred me to parts and service and they said it takes 15a fuses and to read the converter box it has the fuse numbers and those numbers are hand written in (15) except for the bottom one which says 40a. I called keystone but they were closed, i have to wait for Monday morning. I had planned to take the TT this weekend to the lake... So I thought about given this a try... I am on my way home to look for the name and brand of converter, thanks guys! I appreciate it.

[westend]

I don't know why this has to be a guessing game, you have a newer trailer. A call to Keystone, a look through the owner's manual, or a call to the dealer would tell you what this fuse protects and if it is of the correct size.

A single 15 amp fuse would not be big enough to protect your entire 12V system. It protects a circuit that is part of the 12V system or is not correct for the circuit. If anyone tells you to just replace it with a larger fuse, that would be dangerous advice.

[beemerphile1]

What converter brand and model? My guess is the fuse may be too small for the circuit.

[H4X0R]

Yes it still blows with 30 shore line connected, Ok I took the face off the converter to check the wires it seems that fuse #5 and #6 wires are of a bigger gauge than the other 15a fuse wires, it is almost as big as the 40a fuse wire.

[enblethen]

What kind of genset? If it is a inverter style it may not have a ground connection to the neutral. I have Hondas, they need to have a cheater cord body with a jumper between the neutral and the ground pins to lie to the systems in my rig.
There could be a 120 volt item in the rig that is wired incorrectly or has problems. Check between the neutral and the ground in your cord for continuity. It could be something like the refer 120 volt element.

[BurbMan]

KD4UPL wrote:
Is this the main fuse between your battery and the rest of the TT. If so 15 amp seems way too small. It's not hard to imagine that your converter would put out more charge current than that under the conditions you describe.
What size wire is hooked to this fuse?

Kind of what I was thinking. When you plug into the generator, the converter/charger wants to charge the battery right away, and most fuses in that circuit are 30A or more....also common to to have a circuit breaker that resets rather than a fuse.

Does the same fuse blow when you plug into CG shore power? Or is the only time you plug in to a generator?

[KD4UPL]

Is this the main fuse between your battery and the rest of the TT. If so 15 amp seems way too small. It's not hard to imagine that your converter would put out more charge current than that under the conditions you describe.
What size wire is hooked to this fuse?

[westend]

If this is a 12v DC fuse that is blowing, the generator must be powering the converter and allowing amperage to be drawn over the fuses rating of 15 amps. Something in your 12V system is drawing a lot of power. Have you checked the emergency brake switch to make sure the pin is still in the switch?