Heater problem

[NEVERENOUGH]

Ok here is the deal working on my daughters 79 swb 4x4 she just turned 16. I can't get the dang heater blower to work. I can direct power from battery to blower motor and it works. I check the blower motor wire with a test light and I have power. I can't get it to work with the main power just plugged into the blower motor. I changed the relay switch on the ac still no luck. Could it be the switch inside the cab? Any help is appreciated thanks.

[Shamil]

i had the same problem. the problem was with the wire from the fuse box to the switch, i think it is color brown, once i replaced the cable the blower worked.