'02 Electronic Temp Control - No front fan

I just bought a 2003 Grand Caravan ES. It came with the Electronic Tempature Control That has left, Right, and rear controls. When I put the heat on, the rear fan works but the front fan dosn't. I checked the power wire to the fan with a test light and the light flashes on for a second and then it goes out. I switched the front and rear relays but that didn't make any differance. I also checked the fuse and it's O.K.
Any Help would be appreciated.

Thanks,
Marc

Not sure about the '03, but in my '96 with front and back AC/Heater blowers, these fans operate independently of each other. If you swapped out the relays (which I did not know you could do), then the problem seems to be a Resistor Block or Blower Motor problem.