AC blower short cycling-works on heat though

I came home from work today and my house is burning up ac isnt working right. The compressor seems to be running fine, when the blower does come on for a short time (at most 30 secs) the air is cold. Most times it just runs for about 2 seconds and shuts back off.

I tricked the thermostat into thinking it was cold and turned the heat on, at the lower speed the blower comes on and runs fine.

My 1st question is, can I just flip a wire around so the blower will come on at the heater speed till I can replace it?

2nd, since everything seems to run fine with the furnace should that lead me to just assume its the hi speed setting on the blower and replace the blower, or does that not rule out other relay's etc being the problem?

I took a picture of my wiring diagram, but am having problems getting it uploaded.

On the diagram I see there is a Hi volt terminal board with 5 connections (4 used)
C / HI / M HI / M LO / LO (not used)

The wires off this to the blower in order are
White to C
Black to HI
Blue to M HI
Red - to M LO
LO no wire

all those wires run to the blower motor

Would it be ok till replacing the motor to just run the blue wire to HI leaving the black disconnected? And would this make the air run just with the blower at the lower heater speed?

The Furnace is a "Tempstar Hi Boy" model 867-766022.

Thanks so much for any help
Steve