I have a Miller model MGHA-077AAFC-01 furnace I have replaced the limit switch and the aux limit switch it will turn on when thermostat calls for heat but blower does not turn on when chamber heats up. I can manualy switch blower on anyone have any ideas thanks

I have a Miller model MGHA-077AAFC-01 furnace I have replaced the limit switch and the aux limit switch it will turn on when thermostat calls for heat but blower does not turn on when chamber heats up. I can manualy switch blower on anyone have any ideas thanks

You did not replace the FAN LIMIT which makes the fan work in the heat mode.

Fan Limit-115 Part number 22 see page link below.

http://www.mobilehomedepotmi.com/parts_pages/htg_ac/furn_mghammha.html

OR search that site.