30A Fuse

Shane826 · 09-30-2017, 02:17 PM

The fuse right at the battery keeps blowing either when I plug the camper in to AC power, unplug it, or sometime in between. This happens whether it's plugged into 20A at the house or 30A at 2 different campgrounds. If I don't plug the camper in to AC power, the fuse doesn't pop. Haven't really had a chance to check it out to see when exactly it's popping but guessing it's NOT when first plugged in because if I change the fuse the battery is full charged, tells me the converter is charging at least for a while. Battery is less than 2 months old (but that doesn't mean it's not bad). Thought someone may have seen something similar?

cc TrailManor Fans Facebook Page

tentcamper · 09-30-2017, 02:33 PM

Are you saying the fuse does not blow when your are running off the battery and not plugged in to shore power (your house, AC)?? The lights work etc... Battery has good voltage not hooked up to AC? But the fuse blows when you plug into shore power??

If so it sounds like your battery is hooked up backwards.

Normal wiring on the battery is: Black is Positive, Negative is white, green or bare copper wires.

Shane826 · 09-30-2017, 02:47 PM

Yeah you have the description right. I'll double check the wires when we get back to the campsite. I even labeled the cables because as an auto mechanic, black is always ground. Pretty sure I set it up correctly but I'll check.

But then wouldn't things run backwards (fans, toilet pump, etc)?

tentcamper · 09-30-2017, 03:42 PM

My thoughts are that the 12V bus in the converter does not care where it is getting the 12V's. From the converter or the battery.

If you have a full battery it should not be drawing much amps to charge it up.

The other thoughts is maybe the converter has become defective and is developing to high of a voltage. If the converter is to high of voltage the battery at 12.x V would take on a lot of amps and blow the fuse. I would google the converter for what the charging voltage level should be. I would think the voltage should not be going any higher than 14.4 V, but confirm what the values should be?

If it's not the battery wiring. I would double check the battery voltage when not connected to shore power. I next would remove one of the leads on the battery and see what voltage is being developed across the leads from the converter when plugged in to shore power without the battery.

**Bill** · 09-30-2017, 04:13 PM

As TentCamper pointed out, in a camper black is +12 VDC, and white is ground.

Yes, things like fans would run backward, and the toilet pump wouldn't work real well - but when would you notice?

Bill

Shane826 · 09-30-2017, 08:20 PM

My thought about the fan was when traveling with the fridge on 12V DC running the fan. Mega-Maid would be on "suck" instead of "blow". This would also explain why the fridge is never cold when we get where we are going. Scary part is I'd have no emergency brake if the camper ever came apart from the truck.

BrucePerens · 09-30-2017, 11:43 PM

If you have reversed your battery, the monitor panel will not indicate fluid measurements when you push the test button and is probably permanently broken. The TV antenna amplifier and the radio (if you have one) might be too. As far as I'm aware the water heater and the house heater both have electronic controls, I don't know if they die when mis-connected.

Shane826 · 10-01-2017, 06:10 AM

Battery is connected properly. I replaced the fuse last night then connected and disconnected AC power several times, the fuse didn't pop. I'll check it again when we venture outside. It's COLD out there! 37°!

Padgett · 10-01-2017, 07:14 AM

I'd put both a voltmeter (need to check both AC and DC) and an ammeter on the line. Does it pop immediately when you connect the shore power ? Is the fuse holder hot ? I am thinking possibly a failed-short component in the converter.