# 2000 Frontier Heater Problems



## camerond (Nov 25, 2007)

Hi, I purchased a 2000 Frontier three years ago. I previously lived in Phoenix, Arizona. Last winter, my heater gave out on me but I never bothered to do anything about becuase I hardly used it anyway. Well, I moved to Utah recently and make frequent trips to Wyoming. It is COLD so I would like to fix it now.

Here is the details. After the engine warms up, both heater hoses are hot, telling me there is circulation through the heater core. The engine never overheats, which tells me there is no clog in the block. I did have the dealership try and flush it out, so there shouldnt be any air in the system.

Before, it would be warm when I turned it on, but would turn cold within a few minutes. But, it wouldnt be as cold as the outside air which tells me that it is heating up a little bit, just not enough to be useful. I'm wondering if something is wrong with the gates that allow cold and hot air in.

Anybody have any ideas?


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## SPEEDO (Jun 9, 2003)

you might have issues with the control valve, not opening all the way would be my guess..


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## camerond (Nov 25, 2007)

Control valve, eh? Thats somewhere to start. Can anybody tell me about his control valve? Is it behind the dash?

I have heard of things falling down the defrost vents on the dashboard and jamming the vent doors. Perhaps this is the case with the valve?

Thanks.


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## nissanmadness (Sep 18, 2006)

camerond said:


> Control valve, eh? Thats somewhere to start. Can anybody tell me about his control valve? Is it behind the dash?
> 
> I have heard of things falling down the defrost vents on the dashboard and jamming the vent doors. Perhaps this is the case with the valve?
> 
> Thanks.


I'm not sure how a 2000 is set up. On all the 05 and up trucks, all the blend door control motors are electric. The older trucks used vacuum and or cables. These are all located around the plenum. This is where your heater core and a/c evaporator are located. Does your ducting control switch work? In other words, when you put it in defrost or other switch positions, does the air flow out of the ducts as selected? If the air flows as directed, then your switch is ok. Now see if the temp control switch is cable or elec operated. If you can peek behind the switch you'll be able to tell. If its cable, see if the opposite end didn't pop off the blend door lever. If its elec, see if you have power to the switch and go from there. Sorry my instructions are so general, just not familiar with a 2000.


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