Dc wiring for 12v metal cabin fan

[JPolito]

I have removed a faulty fan and plan to replace it. The wiring consists of three wires: green, yellow ( with a black stripe) and black. Can anyone tell me which is positive and neg. The fan will be connected to a two speed switch. The fan I am connecting had a dc plug on it. I modified the plug by cutting it off and have three wires: red, black, and black with a white strip. Any suggestion on hooking this up. Thanks. Joe

[Kazoo Tom]

I believe that the solid black wire will be your negative (ground) wire. The other two are for the two speeds of the fan. You can test each one by using a hot wire to test each one and see which speed is which.

[wa8yxm]

Th ere is no guarantee of anything color wise. If the black wire was installed by the fan maker it is likely chassis ground (Negative) however not guaranteed,

The two other wires are likely hooked to the high and low speed switches.

The only way to be sure you get it right is to use a meter and measure the voltage, this way you can figure it out, I would not trust any color wire in an RV to be anything I expect it to be with out testing.

[JPolito]

Originally Posted by Kazoo Tom

I believe that the solid black wire will be your negative (ground) wire. The other two are for the two speeds of the fan. You can test each one by using a hot wire to test each one and see which speed is which.

Tom, thanks for the help.

[JPolito]

Originally Posted by wa8yxm

Th ere is no guarantee of anything color wise. If the black wire was installed by the fan maker it is likely chassis ground (Negative) however not guaranteed,

The two other wires are likely hooked to the high and low speed switches.

The only way to be sure you get it right is to use a meter and measure the voltage, this way you can figure it out, I would not trust any color wire in an RV to be anything I expect it to be with out testing.

wa8xym, thank you for your help.