I have a 5yr old intertherm unit it has been worked on many times ,it keeps burning the seqencher, they said and keeps turning on the them,heat.now I can't get the blower to work,at all.how do I check the blower to see if it is still good.it has only been in there for about 3 months.

The motor speed could be set to high overloading the sequencer and causing it to burn out.
A loose wire or connection in the blower circuit can also cause a hot spot at the sequencer causing it to burn out.
Turn your thermostat fan switch to on. If the blower still does not start check for 220 volts getting to the motor when the unit is supposed to be heating or if the A/C is on.
It is a good possibility that the sequencer is burnt out again. You might check that also because one of the sequencers also controls the blower when in the heat mode.