booster motor does not cut off

[1_greg_1]

Hi,
First of all, thanks for having this board, I info here is really helpful.
I have a Coleman Evcon Mod DGAT056BDC. I replaced the igniter last year, with help from this forum. Now the heater fires, runs through its cycle but the booster motor sometimes will not cut off. It will sometimes still be running after the fan to circulate the air stops. If I "bump" the fan switch to auto, the booster motor stops. Is this a maintenance problem or a parts problem?

thanks,
greg

[Mark]

Sounds to me like the booster relay is sticking. Part number 7975-3771. http://www.aberdeenhomerepair.com/store ... -24V-relay

Mark

[1_greg_1]

Thanks for responding. The relay you listed is on the left when looking inside the cover. There is another relay to the right. 134-4012-101D 125 VA coil 24v 7956-367. It has 4 terminals with a slot for a 5th (but no terminal coming out of the relay).
1=violet or blue wire which appears to go to the thermostat (has fluctuating dc voltage)
2= two black wires one to the ignition control; the other to the other relay
3=two yellow wires one to what appears to be a transformer and the other to the other relay (looks like the other side of the coil on the left)
4=black wire going to the booster motor
5=no wire coming out, inside is the top contact of the relay which appears to connect to nothing.
The relay on the right is not activating now. 12 volts, which is all I have to test with, does not make the relay react.
If the thermostat is set at its coldest setting and the relay manually activated, the booster motor runs but the furnace does nothing.
If the thermostat is set to make the heater come on, nothing happens. If the relay on the right is then manually activated the booster motor comes on and the furnace heats and when the blower fan comes on the relay can be released from manual activation and the heater completes the cycle.
Could the coil be faulty on the relay on the right?
thanks,
greg