Mystery switch

[Captain Paul]

Is anyone familiar with what this switch is for? It is next to the stove on a 1998 30' Land Yacht.

[Sweeney153]

It may be the microwave a/c switch. you can either use the a/c or the micro wave

[Mollysdad]

Originally Posted by Sweeney153

It may be the microwave a/c switch. you can either use the a/c or the micro wave

Do they do that?

It's a single pole double throw switch with two red and one black. Wiring looks a little puny for 120v AC.
12v?

I guess you could try seeing what works and what doesn't when the switch is thrown.

[OTRA15]

Exhaust fan over the cooktop?

[Captain Paul]

It is not a microwave/AC switch, although that would be a good guess since I do have a switch in the cabinet that allows you to switch between the front or the rear AC unit. The exhaust fan, hood light, etc. are on the cooktop vent. The switch doesn't seem to be hooked to anything that I can find. I was just hoping someone may have a similar switch and knew what it operated.

[A W Warn]

A 2 way water pump switch?

https://www.rvautoparts.com/Kib-Ente...SABEgK_-PD_BwE

[Captain Paul]

The water pump switch is on the range hood.

[OTRA15]

Does your owner's manual cover the switch? If you don't have the manual, there is probably one available online.

[uncle_bob]

Hi

I'd bet it was put in "custom" by a previous owner. In that case it could do almost anything. Switching on the dehumidifier resistor for the fridge is one of many possibilities.

Bob

[A W Warn]

Since the switch has 3 wires I think it is a two way, giving the ability to turn on a device from two different locations. It could be a fan for the fridge if someone added one. It could be for a light, vent fan, pump, water heater, or any 12v fixture or device.

[OTRA15]

Originally Posted by Captain Paul

Is anyone familiar with what this switch is for? It is next to the stove on a 1998 30' Land Yacht.

The third wire looks like is leading to a slightly different spot. Is there an indicator light bulb too? Could you post a close-up photo of the wiring on the back of the switch?

Any other similar switches which don't work?

A two-way is a good suggestion, Alan. Capt. Paul, is all the switching for the pump accounted for already, plus the other uses just listed?

Peter

[Captain Paul]

Yes, The pump switch is on the range hood and one in the bathroom. That is the only switch that I have like that, and that is the only switch on the RV that is not working/haven't figured out. I will take a couple close-up pictures when I get back to town on Thursday or Friday and see if I can trace down the wires.

[Paprika]

For what it's worth, a switch with three wires going to it can perform one of several functions.

1. Two-way selector switch (SPDT). One wire (usually the center) comes from a 12 V source; one wire goes to device A and one goes to device B. You can energize either device, but not both at once.

2. Speed selector switch (SPDT). One wire comes from a 12 V source; one goes to the low-speed winding of a fan motor and one goes to the high-speed winding. Usually this type of switch has a center off position, where neither winding is energized. If there's no center off position, this type can be ruled out.

3. "Two way" switch (SPDT), one of a pair that allows a light to be controlled from two different switches. In this setup, there must be two identical SPDT switches, which are wired together and to the light. Typical use is in a house, at the head and foot of a staircase. Since Captain Paul has only one mystery switch, this type can be ruled out.

4. Lighted on/off switch (SPST). One wire comes from a 12 V source; one wire goes to a controlled load (e.g., water heater); one wire is a ground for the switch's built-in pilot light. Usually the switch is transparent or translucent, or has an obvious pilot light section. If not, this type can be ruled out.

[Captain Paul]

After tracing down the wires I was able to determine that the switch is hooked to a fan on the outside of the refrigerator. It must have a built-in thermostat, which is why it was not turning on when I was flipping a switch. Thank you all for your suggestions and all the information.

[OTRA15]

Originally Posted by Captain Paul

After tracing down the wires I was able to determine that the switch is hooked to a fan on the outside of the refrigerator. It must have a built-in thermostat, which is why it was not turning on when I was flipping a switch. Thank you all for your suggestions and all the information.

Good to know, as you won't be surprised if that fan kicks on when the temps get hot! Probably helps the fridge keep cold in challenging weather. Many of the newer AS trailers have fans for this as you may know, and their operation incl. noise level is often problematic.

Thanks for the follow-up and have a good weekend.

Peter