No heat

[SJMcKee]

My M7040 has a cab with heater (Which i dearly love this time of year)
However it is not working, in that the blower works, but I'm not getting any heat when its up to temp. The A/C works when it was required. But adjusting the thermostat switch for the heater has no effect, just cold air. Is there a switch or fuse related. Or is it possible the temperature adjust on the blower switch has gone bad.

 

[kc8fbl]

I'm not sure if that has a heater core? Could it be plugged? Also, does the temp switch slide back and forth properly? Meaning it isn't disconnected or anything like that.

 

[ipz2222]

In an automobile, if the heater blows cold air, the first thing to ck is low coolant. Never had a tractor that had a heater. The next is the valve that controls how much hot water flows to the heater core. Is it opening and closeing ??

 

[BAP]

On most newer vehicles with heaters, the valve that is operated by the temperature control switch is made of plastic. After time this valve can break or not move properly because of the plastic failing. Does your temp control switch move hard? If so, then it probably has a control cable connecting it to the valve and the cable may not be moving enough to open and close the heat valve. The other thing to check, is where the heater hoses connect to the engine. There is usually a shut off valve in one of the lines coming off the engine. Sometimes these get closed by accident or by vibration. Does the temperature gauge show that the tractor is warming up? If not, could be the thermostat is stuck not allowing the coolant to warm up.

 

[lsmurphy]

One of two possibilities, there is a valve that controls the coolant flow, there is a motor that operates a vent door. The door allow air to blow across the heater core or the AC.....cool or hot air.

One of the two is not working.

On autos the vent door motor and coolant valve is operated by vacuum.....not sure about your diesel.

Could just be that your vent door is stuck. If operated by vacuum, it could be a bad or broken or clogged vacuum line.

You'll have to poke around.

 

[Tx Jim]

Vent door on M7040 is controlled by an elect motor(PN T1275-72200). If engine temp gets up to operating temp then I'd look for blown fuse or other elect problem. I think vent door is in front of dash but that's just a guess from viewing the complicated parts schematics.