six wires in furnace location...what to do?

[pablobagus]

I am wondering why there are three pairs of wires here and not just two pairs for the furnace. about to install new furnace and have a few questions. there are two pairs of aluminium wires and one pair copper. im almost certain the copper are for thermostat. the other four wires are wire nutted together black with black and white with white. can i leave them as such or what to do.....

thanks in advance for any suggestions....

[azflycaster]

The top two sets of wires look like 120 volt wires that may have gone to an outlet that was removed. I doubt that these have anything to do with the furnace. In fact, they may have been added by a previous owner to install an electric heater that was used in place of the furnace. The bottom two are not easily identified, but could be power for the furnace.

[pablobagus]

hey richard, i was thinking that two wires may be 120 as well. i just thought that because its looks original coming from the wall that it could be that they are meant to be there. so definitely do not use all six....

[TG Twinkie]

None of the wires in your pics look like those that go to the furnace. Is that the water pump to the right of the furnace? Your furnace should have 4 wires coming out. 2 for the 12 volt DC and 2 for the thermostat.
Your trailer is of the vintage where the 120 volt AC circuits were wired with aluminum wire. I am not aware of any RV furnace requiring 120 volt AC power.

[Wooden Rivet]

Probably need to get a voltmeter and figure out which wires are 12v and which 120v, then go from there. Do not hook up without verifying.Could be dangerous, and cause major problems with wiring and components.
Tom

[azflycaster]

You need 4 wires. On my 75 these are:

• +12 volts (Red)
• 12 volt return (Yellow)
• Thermostat (Blue)
• Thermostat (Blue)

[pablobagus]

thanks for all the help boys. i will try to figure out which is 12v. interesting thing is that all these wires do not reach the side where it connects to the furnace jumper cable.

[idroba]

I think all of the wires you show are 120 volt ones. When I tried to blow the photo up, it still was hard to read, but they look like 3 romex type 120 volt wires to me. And the fact that you said they are on the wrong side of the furnace is also telling something.

If each set is a black and a white wire, and they are encased in a plastic or fabric type cover I am pretty sure they are 120 volt ones. Also, the bottom one looks to me like there is a bare copper wire with it, which would be a ground wire for a 120 volt circuit.

[azflycaster]

After a closer look at the bottom wires, I agree, they are 120 volt wires and most likely original for the trailer. The wires you are looking for may have been removed or pushed inside of the wall out of the way. I would look inside any opening you have near the furnace, most likely on the side of the connector.

[pablobagus]

you guys rock....i have confirmed with a voltage meter that at least one pair is 120v. when i disconnect the two black wires and tested each, only one was live 120. some of the forward lights turned off when i disconnected the wires as mentioned.

i will search for the missing 12v furnace wires. the last pair of copper in the bottom of photo are in fact the thermostat wires. i found a whole in the wall near bathroom where it appeared a thermostat was placed and found they where the other end to the copper wires.

why is the 120v wires linked to the 12v lights in the front of trailer?