Heater blower wiring

[GOE]

I am installing a new wiring harness on my 67 IIA (neg earth). The harness has two wires to the heater motor but I see only wire coming from the motor. My guess is that the motor is a replacement or upgrade but is there a definitive way to tell before I begin splicing wires?

[a109]

Is the heater a 2 speed type? If so one wire in the harness will be high speed and the other low speed and will connec to the resistor in the blower housing with one wire from there to the motor.
If its a single speed unit one of the wires is power and the other is ground.
The motors single will be power in and will need to ground though the housing or by adding a ground wire (the better way)

John

[siiirhd88]

The two speed blower wires are Light Green with a Yellow tracer and Light Green with a Brown tracer. If your truck has a single speed blower motor, you only need to use one of these wires. The other wire can just be a spare. The blower fan switch should have only one 'on' position if equipped with a single speed blower, but anything could have been changed over the years.

Bob

[GOE]

John and Bob-
Thanks for your input I will give it a go.
Best
George