I have an r-50. It just won't turn on. It worked fine last winter

the fuel is proberly stale drain tank and replace

hope this helps

John

Check the ignition coil for spark if it does not make sure the ground wire that runs to the brake is releasingn if it is replace coil

Is your car well protected with antifreeze? If not, maybe a freeze plug came out. Living in Montana, cars stay outside all winter. I always use a 50-50 solution of antifreeze. Never had coolant freeze up.
Before cranking the car, check that your timing belt did not pop. Don't know how it could, sitting there 14 hours, but turn crank slowly by hand, and check that camshaft is also turning.

When a fuse blows-- you don't replace it

You go to wiring diagrams & check the most
logical thing in the system to draw high current
if it failed

the thermostat is powered by the unit or batteries if batteries they may be dead if the unit you need to check fuses outside at unit or reset breaker outside depending on age of installation

If it won't turn over, probably the battery is dead.If it's not electric start, then you have bigger problem.

I have this problem too, from time to time, it won,t act up for the dealership, when the service message is on I can shut the truck off and come back later and the hubs have turned in and the service light is off and the 4 wheel is fine, it is a '07 gmc 2500 hd

These Ge Zonelines have and ambiant Temp control on the unit when the temp drops it drops out the compressor and goes to electric heat. This keeps the unit from getting iced up. They do go bad and sometimes they shut off to soon. I just replace them and everything goes back to normal. They are located on the outside part of the unit. Just slide out the unit and it is located I beleive on the right side of unit Rus.

There is a diagnostic worksheet behind the aluminum panel on the back. In it it talks about the ambient room temperature must be above 50 degrees.

There are 4 -steps for full run time to kick in a furnace.. step-1, inducer fan runs & prove thru the air tube which closes a switch and tell the circuit board to go to step-2, the igniter lights the pilot & prove its lit by heating the thermocouple, which tells the circuit board to go to step-3, opens the gas valve to dump gas in, which will light from the pilot light, and prove by a flame sensor metal stick on the last burner , which heats up and tell the circuit board Saying, ok , I've got flame.. step-4. when the box heats up, it closes a switch and turn on the main fan...! (Some gas-valves has a brain -or circuit board on top of them and are real sensetive to moisture..)