ci_1612
03-01-2010, 02:39 AM
I have an old carrier 511-331. Its not modulating at all and also seems to be turning on only when the return comes 1 degree over set point and will go down 4 or so degrees under setpoint. Now I havent spent much time on it but have tested power coming to the plug connected to the stepper motor..I have voltage coming through on all 4 lines.. Should only have power on A/B or C/D at one time as A/B open and C/D close it if my memory serves me correctly. So that tells me the stepper motor itself is not the issue, however does this mean somehow it is the microlink or could it be the power module or even something else? just trying to get another opinion as it is a leased box and I cant just start changing random parts. P.S I did check to see if quest software was on this box and it is not.