Always have heat in cab.

Hello there,
My 2002 tacoma has heat coming from the vents at all times even when the fan is off.
turning the control knob does nothing and there seems to be no resistance when I turn it.
air conditioning always blows hot. any suggestions?
thanks,
juan

 

It's usually the blend door actuator or stuck/missing/disconnected rod for heater core water flow valve on firewall.

 

In my case it was the temperature control knob. Yes, The blend actuator door is what controls the air flow but mine was working. I had to toggle my temperature switch from hot to cold and hold it in the cold position so the actuator would stay in the right position. I ordered a new temp control on ebay.

 

If I remember correctly the actuator is called the air mix servomotor. From the passenger floor board it's pretty easy to watch it while you turn the knob from cold to hot and see if it's "actuating". If not, 3 screws to remove and test it.

 

I have a similar issue, 2001 4cyl AC works but it’s either AC or heat, heat comes through on neutral. The one way it seems to work correctly is if the internal only air circulation button is pressed

 

@Tbrad7128 Hey Tyler. Is the temp control you ordered the unit that is in back of the hvac controls? The piece that the hvac bulbs insert into?

 

Yes it is. I thought the problem was with the blend door. I ordered a new one but the issue was the same. My specific problem is in the actual knob that controls the temperature from hot to cold. I can turn the knob to cold, the blend door will rotate and then rotate back. If i hold some pressure on the knob to the cold side then the blend door will stay in the cold position and blow cold air.
I ordered the whole 3 knob unit used on ebay. Its easy to swap by taking the face plate off, held in by three screws and two wiring harness connectors. I will actually be making the swap tomorrow. Im confident this will be the fix.

 

Appreciate the detailed response.

 

I have the same issue with the temperature control knob in my 2004 xtra cab. I just removed the actuator and manually move the blend door once or twice a year. Works for now.

 

I did think about doing that also. I figured my wife would appreciate the extra effort on my end for the couple times she will probably drive it

 

I had a similar issue, except it was stuck in the middle. I replaced the whole dash climate control module with a junkyard one and it's been working great since. Tested the electrical coming out the backside first tho, it's pretty easy to check with the FSM and a mutimeter

 

Finally made the swap with a used temp control. Swap was easy and it did the trick. Order the little LED neo wedge bulbs if you decide to do it. Easy swap while you have it out of the dash.