No aux power from house batteries

[John Trent]

2005 Sightseer, 29R, Ford chassis, 19450 miles.

My problem: No auxiliary power

When I turn off the aux power switch, I can hear the relay click and the house power goes off for extended storage. When I return in a couple of days it won't turn on the aux power - no click from relay. If I start the Ford engine I hear the relay click and the aux power comes on. It's like the power that holds the relay in the on position leaks down. The house batteries check out OK.

On the electrical system, in the forward bay on the passenger side is electrical stuff: chassis panel, a relay panel, and some other 12 volt circuit breakers. There are two large relays or solenoids on the back wall of that bay. One has a black plastic upper part wit a 5 amp fuse and I think it is the battery disconnect relay (I downloaded the parts catalog sheet for that wiring) operated by the aux power switch near the entrance door.

It seems like maybe replacing the "battery disconnect relay" might solve the problem; any ideas?

[John Trent]

2005 Sightseer, 29R, Ford chassis, 19450 miles.

My problem: No auxiliary power

When I turn off the aux power switch, I can hear the relay click and the house power goes off for extended storage. When I return in a couple of days it won't turn on the aux power - no click from relay. If I start the Ford engine I hear the relay click and the aux power comes on. It's like the power that holds the relay in the on position leaks down. The house batteries check out OK.

On the electrical system, in the forward bay on the passenger side is electrical stuff: chassis panel, a relay panel, and some other 12 volt circuit breakers. There are two large relays or solenoids on the back wall of that bay. One has a black plastic upper part wit a 5 amp fuse and I think it is the battery disconnect relay (I downloaded the parts catalog sheet for that wiring) operated by the aux power switch near the entrance door.

It seems like maybe replacing the "battery disconnect relay" might solve the problem; any ideas?

[Pusherman]

John, welcome to the forum.com. You will find lots of helpful folks here on the forum to help answer your questions.

It sure sounds like you have a relay issue. Hopefully someone with more direct experience will give you some direction on your problem.

[John_Canfield]

Let me replay what I think you are saying:

- Battery disconnect relay works to shut off batteries

- Battery disconnect relay doesn't work (no click heard) after returning to the RV from an absence

- Battery disconnect relay does work if the engine is started

Doesn't sound like you have a relay problem since it does work with the engine running.

I would use a meter and probe the coil while an assistant operated the switch. I'll bet you have a low voltage situation - not enough power available to operate the relay. If this is the situation, further investigation will be required to discover why you have low voltage.

In my experience, relays will generally completely fail. Failure could be the relay doesn't operate at all, or the contacts build up crud (my technical term) and don't complete the circuit. This typically is the failure scenario of the charging solenoid - it operates but the contacts are ineffective.

Hope this helps and welcome to the forum. Hopefully you will get some more ideas from the resident brain trust on the forum.

[John Trent]

I will check further for low voltage condition.

Sincerely,
John Trent

[TigeDuner]

Depending on where the power is coming from to feed the relay, maybe the coach batteries are dead or weak. Starting the engine would provide a charge to those batteries allowing the switch and relay to work. Just a thought.

[John Trent]

Thanks .
I cleaned the all the terminals with a steel brush and I think this has corrected the problem.
I bought a new battery disconnect relay as a back up.
JBT

[John Trent]

The batteries check out OK.
I cleaned the terminals with wire brush and re-connected - the problem seems to be gone.
I'll keep my fingers crossed that that was the answer. Some times things are simple.