Community Forums

L.R.S. · 02-07-2021, 06:52 PM

After boondocking in our coach for several months we suddenly lost all interior 12-volt power. The RV was parked at the time, had not been moved in several weeks, and has not been moved since (we are in a campground).

I checked the fuse panel in the back bedroom with a multimeter and it has no power coming in from the # 8 gauge wire. This wire drops down into the wall and I assume it goes to the exterior battery bay which is directly below. I checked everything in the battery bay and all terminals have the proper 12 volts.

Is there some sort of junction box under the RV? Or possibly in the wall? I was able to use regular automotive jumper cables to temporarily get power to the interior 12 volt fuse panel and everything works as it should.

irishguy · 02-07-2021, 07:14 PM

There's probably a number of possible causes but I had the same thing happen last summer.
It turned out the house battery cutoff switch packed it in suddenly and opened the circuit. It was an easy fix.

cavie · 02-07-2021, 07:31 PM

Between the battery and the fuse box is a Battery Disconnect that seems to be turned off or has malfunctioned.

Ivylog · 02-07-2021, 07:45 PM

The salesman/disconnect switch by the front door activates a relay in the back run box. Fairly common for it to fail and you can jumper it as most rarely use the disconnect function.

twinboat · 02-07-2021, 07:45 PM

An 8 guage wire will have a fuse or breaker, and possable a disconnect near the source of power. The source is the battery.

L.R.S. · 02-07-2021, 07:52 PM

Quote:

Originally Posted by cavie

Between the battery and the fuse box is a Battery Disconnect that seems to be turned off or has malfunctioned.

I've checked every + positive terminal in the battery bay and they all have 12 volts where they should, including downstream of the battery disconnect switch.

This is a picture of the battery bay. The white arrow is pointing to what I can only guess is the 12-volt feed going into the coach for all 12-volt power. The #8 wire coming off the + lug goes out of the battery bay but I haven't traced it any further.

I'm wondering if there is some sort of junction box where this wire goes with a terminal that may have come loose? I will have to start the coach and air up the system so I can crawl underneath and see if I can trace the wire.

L.R.S. · 02-07-2021, 07:56 PM

Quote:

Originally Posted by cavie

Between the battery and the fuse box is a Battery Disconnect that seems to be turned off or has malfunctioned.

Quote:

Originally Posted by Ivylog

The salesman/disconnect switch by the front door activates a relay in the back run box. Fairly common for it to fail and you can jumper it as most rarely use the disconnect function.

I have owned this coach for 6 years and am not familiar with any sort of salesman/disconnect switch near the front door?

Endeavor40 · 02-08-2021, 12:29 AM

Did you check your breakers on the inverter?

L.R.S. · 02-08-2021, 12:37 AM

Quote:

Originally Posted by Endeavor40

Did you check your breakers on the inverter?

The inverter is working fine. The RV has 120-watt power at all outlets.

cavie · 02-08-2021, 03:14 AM

Quote:

Originally Posted by L.R.S.

I have owned this coach for 6 years and am not familiar with any sort of salesman/disconnect switch near the front door?

It is there for sure. Just a small rocker switch that controls a relay like a starter solenoid. It is used to disconnect the batteries during storage.

L.R.S. · 02-08-2021, 03:46 AM

Quote:

Originally Posted by cavie

It is there for sure. Just a small rocker switch that controls a relay like a starter solenoid. It is used to disconnect the batteries during storage.

I'm back at home until this coming Friday then return to the campground for 4 days over President's Day weekend. I'll look for the switch. Really hope it's something that simple.

Lowflyer1 · 02-08-2021, 07:59 AM

Quote:

Originally Posted by cavie

It is there for sure. Just a small rocker switch that controls a relay like a starter solenoid. It is used to disconnect the batteries during storage.

I had a problem with all the interior lights operating intermittently from the battery cut-off switch. I got a new switch and still intermittent.

Then traced it to a bad relay in the driver side front electrical bay that the switch controls. Once I replaced the relay, it works fine.

cavie · 02-09-2021, 03:35 AM

Quote:

Originally Posted by L.R.S.

The inverter is working fine. The RV has 120-watt power at all outlets.

That would be 120 VOLT power.

YC1 · 02-09-2021, 03:57 AM

These may not match your unit but are posted for reference. I highly suspect there is a simple switch near the door that has been bumped or some situation caused the "house relay" to disengage. Or in many cases they just give up the ghost.

The "house relay" (many hate salesman switch/relay connotation), may be in a compartment below the driver in an outside compartment. I'm sure someone here has a more detailed layout than me.

The concept has not changed as far as I can tell for a long long run of these snow flakes.

The "house relay" is often simply bypassed to eliminate accidental disengagement. With it off in mine the air conditioners do not work as well as many other items and leaving it with a fur baby inside is worrysome.