What wire is hot on 2000 grand marquis heater motor?

Answer 1

The heater motor is on the passenger side firewall in the engine compartment, located in the AC/Heater box.

There is a cable coming off the round part sticking out; that's the power. It's in a harness; you can pull it out by hand by depressing the lock on the side.

The black wire is ground; the other is hot. Take a multimeter and put one lead each into the harness. If you have a digital meter, it won't matter which lead goes to which hole, as it will show negative voltage if it's reversed. If it's analog, put the red lead on the striped wire, and just touch the other with the black. If the needle jumps backward, you've got it reversed.

If you show full voltage, you've got it right, and power to the fan. If there's nothing, you probably have a bad controller, a bear to get to, but not very expensive to replace.

Hope that helps!