heater/cooling problems, need some help!
 

ok, well, its abt 30 degrees here in the mornings now, and something weird has been happening, the heater works great and the temp gauge stays in the middle while moving, but when i stop at a light, and its at idle, the truck starts to get warm (never overheats) but the needle goes up quite a bit, and the heater stops working and it just blows cold air? even in the summer in 100 degree weather the truck never went past the middle, why is it now?

Re: heater/cooling problems, need some help!
 

Could be that your fan clutch is not working so the fan isn't pulling enough air and that's why it's getting hot while stopped. I don't know about it blowing cold air though. That's wierd

Re: heater/cooling problems, need some help!
 

sounds like the heater core is clogged up or something along those lines.

Re: heater/cooling problems, need some help!
 

Have you checked your coolant level? Both symptoms could be indicating that you are down below full.

Re: heater/cooling problems, need some help!
 

im betting coolant level and or thermostat

Re: heater/cooling problems, need some help!
 

definately sounds like low coolant level. a plugged heater core wouldnt work at all. what happens is when the water pump stops pumping hard like when your driving the air bubble rises up and and the sensor no longer is submerged in coolant to get a proper reading. they dont read air very well at all. top off the radiator and fill the coolant bottle to proper level run the truck let it burp and fill refill if needed