Last post on Oct 08, 2013 at 4:37 PM
You are in the Ford F-Series
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Ford F-150, Ford F-350, Ford F-250, Heating / Cooling, Truck
#55 of 85 temperature selector switch
Dec 12, 2009 (9:24 am)
I have a question about the temperature selector on a 1997 Ford F-150. How do you test the switch? We have taken it out found 3 prongs labeled 1, 2, & 3. What do these mean and are you able to test it to see if it is bad?
#56 of 85 My heater switch under the hood will only let heater blow on high
Dec 18, 2009 (9:25 am)
I just replaced the heater switch on '06 F250 because it was only putting out heat when on high. Now my new switch is doing the same thing. Anyone have an idea what might be causing this. Fuses # 22 & 28 are not blown.
#57 of 85 Loss of heat
Jan 23, 2010 (8:39 am)
I have a 2001 F-150, once the heat gets up to the normal range I turn the heater control switch from off to floor or vent/floor. For about 30 seconds I get warm air and then the airs cools quickly. I can turn the controls off for about five minutes then back on and it works fine for another 30 seconds. I have noticed that both heater hoses seem to be about the same temperature so I don't think the heater core is totally stopped up. I can tell a sight difference in the air coming out of the vents if I change the heater control for hot to cold and back.
#59 of 85 Re: F-150 Climate controls [autoxpresstech]
Mar 26, 2010 (12:49 pm)
I have the same probelm. I have a 99 F-150 and it blows cold sometimes and hot sometimes. The vent selector works just fine, if I want defrost I get it, if I want floor or panel I get it. The problem is with temp control. I replaced the potentiometer for the temp control and no change. The probelm has to be with the "mixing valve" (at least that's what I'm calling it) that regulates the desired temp selected on the climate controller. Does anyone know where this valve is located or how to replace it. Or does anyone have any other ideas? Thanks
Apr 07, 2010 (1:54 pm)
2001 Supercrew, 82 k
I've notice a dripping under the truck after I've driven it. Looks like the dripping you see from A/C condensate, but this has been occurring during the winter. It is clear, and odorless, colorless and tasteless. Today, about 70 degrees outside, driving with window open, I had the temp setting to cool, A/C off, and the vent was switched to Panel/Floor. I expected the air coming from the vents to be about the same as the outside air. However I found it to be quite cold, and obviously the A/C was running. Switching the vent to "Floor" or "Defrost/Floor" I could hear the A/C compressor turn off (click from under the hood). By trying the different vent control settings, it appears that the A/C compressor is turning on when I switch the vent control to Panel/Floor, or of course if I switch the A/C on deliberately. This seems odd since the A/C is normally not on unless the "A/C" setting is selected. Also, you can't select "A/C" (on the left side of the control dial) and "Panel/Floor" at the same time (on the right side of the dial) since they are both control by the same knob. Since I usually run the Panel/Floor vent setting when I have the heater on during the winter, it seems this is why I was seeing dripping under the truck.
Is this a rotary control switch problem?
Is the A/C supposed to turn on when Panel/Floor is selected (and perhaps I didn't notice it before)? Thanks.
#61 of 85 Re: '99 F-150 climate controls prolem [dryfly321]
Jul 04, 2010 (7:46 am)
dryfly you are a genius. I looked on the right side and the vacuum box ,directly behind the battery on my 2001 F-250 super duty, had a hole worn or burned in the top and it was leaking air. I temporarily plugged it and it fixed the selector problems. Can't see anything that wore the hole it it but with a little RTV I expect to be back in business soon. Thanks for the idea.
#62 of 85 Re: F-150 Climate controls [ltherneck]
Jul 21, 2010 (3:03 pm)
I have a similar problem. I also have a 99 f150 and the ac works and the heat works. The vents all work when I change from vent to defrost to floor. My problem is when I start my truck all I get is cold air even when it is heated up. This is with temp set on cold or hot. When I drive at highway speed, say 55 or more then stop at a stop sign or light it starts blowing hot. Driving through town it will keep blowing cold so long as I don't get up to highway speed. So is this a vacuum problem or temp control problem or blend door problem? Could the quick stop and start at highway speed cause the blend door to change if it were broken? Thanks for any feedback.
Jul 24, 2010 (5:34 pm)
1989 F350, replaced AC compressor, drier and orfice tube, put oil in the new compressor, and charged the system, it never really got cold and then a line burst.
Any ideas what could cause this?
#64 of 85 Vacuum harness not tight to control head
Jul 26, 2010 (11:18 am)
Deforst is the default mode - gov't mandate. I suspect you have a vacuum leak where the vacuum harness connects to the back of the control head. Try to see if you press it tight, if it works ok. See if you can use tie straps to hold it tight to the control head.
Last resort - cut one at a time off the harness and connect each one to the control head with a 1/8" (I think) piece of clear hose.