Backwards battery hook-up..no thermostat

[DSG]

Hi there,
Hoping someone can help. Have a new 2015 Sunset Trail 240BI.

In a hurry getting to head out yesterday and I reversed the battery connections.

Fixed the connections and replaced all 4 reverse polarity 20A fuses- and headed out. Drove 300 miles, setup and hooked up. No radio no thermostat display or furnace/AC. Lived with it for the night. Got up this morning with a fresh head and recheck everything without a multi-meter. Found one of the fuses I stuffed in was bad. Replaced- no joy. Pulled radio and found blown 10amp...sucess..its back.

Pulled cover for thermostat, hoping to find a DC fuse, but only a 2A 250V.

Any suggestions would be aprreciated..the DC power converter is a Worldfriend 8965, and the thermostat is a RV comfort. HC Coleman Mach

With a forecast well into the 90s tomorrow, would love to keep the queen and the 3 jesters cool. Thanks in advance.

[cw3jason]

Check the fuses in the fuse panel. Just because the Led is not lit, does not mean the fuse is not bad.

Sent from my SM-G900V using Tapatalk

[DSG]

Good idea cw3jason...Just swapped all the 15 amp fuses around just in case could not see break...no difference.

[r2millers]

Your heater thermostat is probably driven with 12v's and I'd expect your thermocouple to be a millivolt driven unit.
Hence, have you checked your converter fuses?
Different brand then mine but mine has two 35 amp fuses underneath.

[DSG]

It was the fuse in the thermostat. Went out and bought a multi meter, and no continuity. Still shaking my head because it looks fine.

Thanks for the suggestions guys!

Darren

[cw3jason]

Glad to hear you got it fixed

[Duey]

The thing to remember about RVs, they are not vehicles. They are wired like houses, someone said that to me once and I've always remembered. Now I don't put the wires on the wrong connection. The black wire is +.

[shoe2728]

Not sure what year they changed it but my 2001 cardinal 5th wheel was like a car battery, black neg and red pos. Now my 2012 5th wheel is black pos and white neg.

[Tim D]

Originally Posted by shoe2728

Not sure what year they changed it but my 2001 cardinal 5th wheel was like a car battery, black neg and red pos. Now my 2012 5th wheel is black pos and white neg.

Well...In the absence of a "red wire", Black is positive.

[Bowler304]

If one were to put a quick disconnect would it be on the negative (white) side or positive (black) side?

[shoe2728]

Put it on the ground side of the battery, which will be the negative terminal. Don't go by the assumption that your battery is wired like previously stated (like a house)not true. Car batteries are labeled - and +.. house wiring is not they are hot, neutral(common) and ground. Never seen a car battery with three posts.

[r2millers]

Either would work but I have mine on the positive. If on the ground side and you completed the ground circuit anywhere in the trailer, it would still arc.
Not the case on the positive if close to the batteries.

[shoe2728]

Originally Posted by r2millers

Either would work but I have mine on the positive. If on the ground side and you completed the ground circuit anywhere in the trailer, it would still arc.
Not the case on the positive if close to the batteries.

If the neg. Side of the battery is disconnected, the only way you can complete the circuit is to touch the neg.Side of the batt. to gnd. Everything else that is 12v is already grounded.Now if you put a kill switch on the positive and thru vibration the wire comes off and touches ground you will have all sorts of sparking and possible melt down of the battery.

[Randy68]

If your reinstalling batteries especially 2-6volt in series take a picture before you remove them. I have 4 six volt batteries each pair in series and two pair parallel to each other 12 volts and lots of amp power for dry camping,

[Duey]

Originally Posted by shoe2728

Put it on the ground side of the battery, which will be the negative terminal. Don't go by the assumption that your battery is wired like previously stated (like a house)not true. Car batteries are labeled - and +.. house wiring is not they are hot, neutral(common) and ground. Never seen a car battery with three posts.

A lot of people assume the black cable is for the negative like on a vehicle. That's why I mentioned that. There are many post that people thought this. So we just trying to help with suggestions so people don't mistakenly connect wires to the battery wrong.

[Vince]

I have a similar problem I think. E7 message. Where do I find the fuse in the thermostat and what size was it?

[r2millers]

Originally Posted by shoe2728

If the neg. Side of the battery is disconnected, the only way you can complete the circuit is to touch the neg.Side of the batt. to gnd. Everything else that is 12v is already grounded.

If you disconnect the grounded side, every circuit within the trailer is possibly Hot, if grounded Anyplace within the coach, not just the battery ground.

You simply have to complete the circuit.

Ground yourself well and touch the hot side of a circuit when the ground side switch is off, then tell me everything is grounded. YOU become the ground.

[shoe2728]

Originally Posted by r2millers

If you disconnect the grounded side, every circuit within the trailer is possibly Hot, if grounded Anyplace within the coach, not just the battery ground.

You simply have to complete the circuit.

Ground yourself well and touch the hot side of a circuit when the ground side switch is off, then tell me everything is grounded. YOU become the ground.

Ok, help me understand what you are saying, if I disconnect the neg side of my 12v battery go inside and grab tightly to the frame then touch the neg. Side of a 12v light the light will come on.

[r2millers]

Originally Posted by shoe2728

Ok, help me understand what you are saying, if I disconnect the neg side of my 12v battery go inside and grab tightly to the frame then touch the neg. Side of a 12v light the light will come on.

Yes. That's correct. If you have enough resistance to complete the circuit, the light will go on. You have the positive side of circuit still "live" throughout your RV.
Once the circuit is complete with an "earth ground" the light will come on.
Hence, the reason we all have gfci's in our rv's. The gfci senses more then usual resistance in the line and "interrupts" or shuts off the flow of electricity before it completes the circuit (gets to your feet). If it didn't do it extremely quick, you would feel the shock.

https://simple.m.wikipedia.org/wiki/Electrical_circuit

[Bowler304]

So quick disconnect on the positive side, gotcha! Or 'red / black' site with the + on it.