I just installed a new blower motor on my '68 RS with Fact a/c. I tried it before putting the inner panel back on first.

The blower/fan blows on speeds low-med, but NOT on Hi-Speed. Any suggestions?

Thanks

 

The blower switch probably went bad. If one of the lower setting were bad, the resistor pack would be suspect.

 

When you "bench tested" the motor, was it hooked up to the dash switch and all 3 speeds worked?

 

I just put 12V to the motor to make sure it worked before install. As I said, lower 2 speeds work, just not Hi-speed.

On the old motor removed, it worked great on the 3 speeds, but made loud noises.

 

I found the issue. The ground wire on top of the A/C box was loose that comes of the sw. Now all is well.

What a rough job changing the heater core and blower motor. GM must have built the car around those items !!!!

Thanks for suggestions.