I have a very old GE gas furnace model # BLU080E924B1 that doesn't want to work on auto. Thermostat seems fine, but unit won't run unless I connect gas valve and blower directly. I installed a new relay, new fan/limit control and new transformer. I don't understand why it doesn't work on auto.

Have a very old GE Furnace that doesn't run on auto. Need to figure out why.

don`t quite understand hooking gas valve and blower together,, have you bypassed the thermostat, to see if furnace works as it should with out the stat doing the controlling,just tie together or jumper the red(hot=24 volt ) to the wire,(should be maybe white) that is going to and opens the gas valve to open,this bypasses the thermostat,and if the furnace works as it should,, gas valve opens,burners light up,and then after a few minutes the blower comes on,( this is assuming you have a standing pilot light),that burns all the time,if all works right,, you probably need a thermostat replaced,, let us know