This is a good one. Battery is good, connections all are good. Good voltages to the card and to contactors. Contactors pick-up. Tried new card and same problem. Had replaced the transistor prior to this problem. Did have noise out of the transistor but no output to the motor. Replaced the transistor and problem gone. Installed old control card and still is working. Not sure why. Went through the panel one more time to make sure the was no wiring or connection problems. Unit is still working great. Not sure how this could give a code 27.