AC Blows Hot When on Cold Setting and Cold When On Hot Setting

Bump for the answer!

 

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just switched mine out too and it blows hot on cold and cold on hot. any answers or did you figure it out?

 

I have a working solution for this! As Jones mentioned, pre-2009 Trucks use opposite voltage from the 2009-2014(?) trucks to control the temperature. The result is a backwards dial. The solution is to switch the contacts on the control knob so that it feeds reverse voltage from the original design. This is done by cutting the original circuit board connections, and rewiring the connections to the opposite pins of the control knob. One other note, like the OP, My A/C Control wire needed to be on Pin 13 (not 16) on the A33 Connector. My truck is a 2006, so I also needed to make a connector from the A16 connector to the A33 connector.

Sorry I didn't take a picture, I was in too big of a hurry to get it back in the truck!!!

The solution to this is as follows:

1. Take apart the A/C Control panel, and isolate the circuit board.
2. On the back side of the board you will find 3 pins coming from the Potentiometer (Control Knob)
3. You will see 3 leads coming from the Control Knob. To get the correct orientation, rotate the board until the lead with the thickest "trace" is at the top (12:00) position, and the bottom lead is a "trace" that leads to a resistor. (note: on the graphic, you will not see the control knob as it is on the opposite side of the circuit board)
4. With a razor blade, cut through the top 2 leads (Do not cut the bottom lead). This will disconnect the control knob from the circuit.
5. With a razor blade, lightly scrape the "trace" of the top 2 leads to expose a small section of copper "trace". Then meter between the exposed "trace" and the lead from the corresponding control knob lead and make sure there is no connection. If you still have a connection, you need to cut deeper in step 4.
6. Add a bit of solder to each of the exposed copper "traces" and cut two small wires and tin the ends with solder. Solder one wire to to one of the Control Knob leads, and to the opposite trace at the exposed copper trace. Repeat with the other Control Knob lead, and opposite trace.
7. Meter between the Control Knob Lead and another point along the trace to make sure your solder connections are solid.
8. Reassemble the A/C Controller and enjoy proper Cold/Hot Settings

 

Thanks for sharing this info and graphic. I now have proper hot/cold settings

 

You're welcome, sorry for the terribleness of the graphic

 

Would either of you being willing to perform this fix for me? I have a set of 2012 climate controls that I'm wanting to make plug n play on my 2007.

I would pay shipping both ways? I know I couldn't be the only one on TW that's wanting to do this mod...

 

Anyway to get the write up with photos?
Have my parts just need to see what yo do! Thanks

 

I wish I'd have read this before I put a 2010 temperature controller in my 07. It would seem to me, however, that there's a way to switch the wires in the harness, as well. Has anyone remedied the issue that way? I had to replace mine because my previous board was boogered up and I just don't want to go cutting into the new one.

 

Ok, I didn't get any responses (I know it's an old thread) but I got the volt meter out and did some checking myself. It seems that the internal mod is the best option. Funny thing is, that side by side, the pre-2009 board and post-2009 board are identical. Even the resisters are the same. Long story short, the mod is done and working perfectly. Thanks for the write-up on this. I found it easy to follow.

 

Since @d2 post was super helpful, I'll post of this picture of what the directions describe. This worked perfectly for me

 

I have the Aucar Tesla Screen installed and I have a 2008 and of course the hot is cold and the cold is hot. I've been driving like that for about a year now, but it just bugs me. I was hoping someone had solid details on tricking the truck into switching them around instead of doing it electronically since Aucar has very limited support other than buying.

 

The Mode and Temp actuators use a 0-12v linear control voltage on Pin 2, as the voltage increases or decreases the actuator moves accordingly.

You would need a way to reverse the voltage output to the actuator or use an actuator from a 09-15 truck, it's not well documented but the 05-08 actuators and 09-15 actuators use opposite control voltages (05-08 12v is max cold and 0v is max hot, 09-15 0v is max cold and 12v is max hot).

In fact it's very had to find a temperature actuator for an 05-08 truck because the superseded part# according to Toyota fits 05-15 trucks but will operate backward on 05-08 trucks, even some sections of service info have the wrong voltage specs on them.

 

Sounds like I shouldn't have thrown away the perfectly good 2008 controls once I got the Aucar working.

 

Is there not a setting to reverse the output?

 

I'm having this issue on my 2008 taco. the cold setting blows hot and the hot settings blows cold. Very odd. Any simple fix to this? no biggies if not it's just so weird

 

Did you recently replace the temperature actuator?

 

I'm not sure what that is, unfortunately. But I did replace the stock temp controls with a 2nd gen aucar headunit

 

Ah I'm not sure about that but I explained how they work in the post (#33) above.

 

Yeah, I saw - I didn't understand it but sounds interesting. the headunit just plugs into the ac and temp controls