thermostat wiring

sourmash

I just bought a honeywell 7500 , 7 day programable thermostat for my heating & central air .The thermostat has a full auto mode that lets you keep the house at a steady temperature all the time.It will turn the heat on when needed or the ac when needed to keep the room at the set temperature.I have two seperate units for heat and air and I cannot find a diagram or any information on how to wire this to make that function work.The way I have it wired now i have to manuelly change from heat to ac.I was also wondering if there is a way to keep the backlight lit on the thermostat so I can see it at night without turning the light on.i was going to put a jumper from the R to the L connectors but I wasnt sure if that would work

Nathan

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