2011 Tacoma Dual Cab A/C Thermistor Location and Change Out

My AC was freezing up but after warranty expired.
Had pressures checked twice and discovered they were fine but the compressor was not cycling.
I diagnosed down to a failed evap coil thermistor. The job to remove, change thermistor seems to require pulling out the entire dash to split the evap case. I was able to confirm thermistor by changing it out and inserting it in an AC duct and it improved about 70% but still freezes up after some time (20-30 minutes), as the thermistor is too far from the evap coils. Does anyone have pictures of the evap case, split open so I can determine where it actually goes inside. I would like to drill thru the case and place next to the coils without drilling into a coil.

My concern in removing the dash is I will induce other rattles and connection issues in addition to the 20-30 hours of labor to install correctly.

 

Yes one has to remove the dash to get to the thermistor it goes in the top with the lead out the RH side of the case. And yes you could introduce other rattles, or even cure some.

Are you sure its the thermistor? Have you tried measuring it to specs?
I would not automatically assume that it is bad as there are other reasons the evap can freeze, the most likely being the amount of moisture in the system from low refrigerant/leaks, overloaded dessicant in the condenser, not pulling a proper deep vacuum prior to recharge, and contaminated service hoses.

If this were mine I would first do these three things before digging into the dash:
1. Check factory specs of the thermistor.
2. Feel the pipes.
Try this. Get the truck warmed up and turn on the AC and run for a few. Pop the hood and find the two aluminum lines that go into the firewall. The small line is the high pressure feed from the condenser to the evaporator; the larger diameter line is the return line back to the compressor from the evaporator.
While running feel the two lines on their aluminum parts where they come out of the firewall near the black rubber grommet and black plastic couplers.
You do not want to observe a super cold feel or icing or heavy frost on the return line.

Report back what you observe.

3. If these seem ok, use some R134A manifold gauges to check pressures per the Toyota FSM and not guess-a-pressure.

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I have a bad evap thermistor causing freeze ups, verified through unplugging and reading ohms and comparing to Toyota specs.

Has anyone changed this themselves? I have the sensor ordered but still trying to figure out how to get it out....