i live on a small budget and finally aquired an older goodman furnace (gmpn080-4) and ac which were in very good condition out of a friends place and had only been used for 2-3 yrs. even the condenser outside was kept covered and secured when not in use . that said the units were in full working order together . they have been installed at my place all duct,furnace,a-coil,condenser (and charged) ,gas and main electric work is done . but now i need some help on how to reconnect the low voltage wires .under normal circumstances i think i would have no problem but this furnace model has no Y terminal !!! i only have 3 wires from the board W G R i bought a basic thermostat for heat/cool ran a 5 wire of it and connected it at the thermostat as required also ran wire from condenser to furnace (airhandler). now i look at 5 wires from thermostat and the yellow and red from the condenser as well as the 3 wires red ,green and white from the furnace .missed the chance to be there during dismantling and i do not want to make a mistake and ruin what i have . where do they go ??? ( i do not want to break the rules here by posting a link but pictures often tell more then words .there is an ebay listing that shows my exact board under the tittle : OEM Goodman Janitrol Furnace Control Circuit Board Panel B1809913S to see what i have ) i used to have grey hair but it turned white from googling this for days is there a way you could steer me to a wiring schematic that shows where i need to connect (assuming doubling up )the wires from the condenser to the board . the heat side i think i understand where to go. just not were i need to double the connection for the 2 wires from the condenser any help be truly appreciated and thanks in advance !!!
The furnace doesn't need a
Y terminal, and in a lot of cases when it does have one, it's not connected to anything in the furnace. Connect the wires from the thermostat as follows:
- Red connects to
Rin furnace and
- White connects to
Win furnace and
- Green connects to
Gin furnace and
- Yellow connects to the Red wire to the condensing unit.
- White wire from condensing unit connects to 24V common terminal of the transformer.
The 24V common terminal of the transformer should be grounded to the chassis, as well as connected to PIN 6 of the Molex connector on the board.
*The "hot" 24V terminal of the transformer should be connected to PIN 3 of the Molex connector on the board.