Red light on battery disconnect not coming on

[Geno48]

You can hear it click when you push the button to "Use". Not sure if the batteries are being charged. They went down last week then I found I had a short in the hot water heater circuit so that is off. I am plugged into 110 and if I shut that off things work off of 12v. The voltage readings seem to be holding in the good range and 13+ if I'm plugged in. What am I missing?

[jftompkins]

I think….? there are two small fuses on the latching relay itself (the click) secured inside one of the lower cabinets, one fuse for the indicator light to check. With a multimeter you can also check across the two main terminals for voltage when switch closed at 0V.

[Hermes]

The battery disconnect switch, also called the Use/Store switch, on the wall controls a solenoïd which does the actual connect/disconnect of the batteries to the 12V circuit. When the batteries are connected to the 12V circuit the converter which feeds that circuit by converting shore power to 12V, charges the batteries.

The solenoïd switch magnetically moves a metal bar in one direction or the reverse direction between two poles to make or break the 12V circuit connection with the batteries.

In order to activate the magnet in one or the other direction, there are two 5Amp fuses on either side of the solenoïd, one to move the metal bar in one direction and one for the other direction depending if you press the toggle switch on the wall to Use or Store.

The first step is to test those fuses to make sure they are Ok if not the solenoïd won't switch, which may mean the batteries stay connected to the 12V circuit, or they stay disconnected from the circuit, depending on which fuse is cooked and the position of the bar when it happened.

The filament in a 5V fuse is quite fine and eyeballing may not be sufficient, it is better use a multimeter to check it (a very useful tool in an Airstream).

[jftompkins]

Originally Posted by Hermes

The battery disconnect switch, also called the Use/Store switch, on the wall controls a solenoïd which does the actual connect/disconnect of the batteries to the 12V circuit. When the batteries are connected to the 12V circuit the converter which feeds that circuit by converting shore power to 12V, charges the batteries.

The solenoïd switch magnetically moves a metal bar in one direction or the reverse direction between two poles to make or break the 12V circuit connection with the batteries.

In order to activate the magnet in one or the other direction, there are two 5Amp fuses on either side of the solenoïd, one to move the metal bar in one direction and one for the other direction depending if you press the toggle switch on the wall to Use or Store.

The first step is to test those fuses to make sure they are Ok if not the solenoïd won't switch, which may mean the batteries stay connected to the 12V circuit, or they stay disconnected from the circuit, depending on which fuse is cooked and the position of the bar when it happened.

The filament in a 5V fuse is quite fine and eyeballing may not be sufficient, it is better use a multimeter to check it (a very useful tool in an Airstream).

Agree and thanks for noting - the latching relay manual said "There are two 5Amp fuses for the system, mounted on each relay. Looking at the relay with cap at the top, the
fuse on the right feeds the LED indicator and if so equipped, the digital voltmeter. The fuse on the left feeds the
power to the switch that operates the solenoid." ...my understanding is that the relay on loss of power stays in position and with a spring/magnet inside is able to hold that position. The bottom line as you stated get a multimeter and check continuity of those little 5A fuses.

[Geno48]

I had to replace the solenoid. The guy at the parts counter said this the replacement. Well it doesn't have a fuse on the right side. I am getting 12v power and the batteries are getting charged but I suspect that is why the light doesn't come on.
thanks to all for helping me troubleshoot this little drama.