Let there be heat..... Please

What's the name of that Shady shop? I got some friends in Houston

 

Nothing would surprise me. Might find one of the guys' microwave mac 'n cheese back in there.

 

Driver's Auto in Pearland. They were the cheapest place I checked but they were only on my bid list because the website said Toyota certified technicians or something along those lines. Even asked specifically before going with them and got something like "..oh yeah, all the certifications and stuff...". Not doubting it, but not sure exactly what means and definitely won't be going by statements like that anymore.

 

I bought the ebay one from thegreenyota. Thanks man.

 

So I changed out the control box and still the same problem. Disconnected the cable from the heater control valve and the valve moves freely. The temp control knob moves from cold to hot just fine on the new control box but the cable does not move. By the way, @Wulf called it. Some jackass somehow broke the knob and glued it on to the stub. Glue eventually melted enough to ooze and freeze the knob up.

Guess I'm pulling the rest of the dash to figure out why the cable isn't moving.

As per before, any tips, tricks, insight or guesses are most appreciated.

 

I have the mechanically driven controls (99 Tacoma), however is there a cable that connects the motor/servo to the heater control valve? I had symptoms like you until the sheath of the cable broke because I muscled the knob too hard. Replaced the cable for $13 and it feels like new. I think the cable/sheath fills with dirt and eventually seized up.

 

Yes, there is a cable and being frozen inside the sheath is entirely possible I guess. I wonder if squirting some PB Blaster or WD40 in there would free things up?

 

I pulled the air mix servomotor and left the cable plugged in. Turned the vehicle on and fan Off, Low, Med, High works fine, the directional controls (face, feet, defrost, etc..) works fine but when turning the temp control from cold to hot and vice versa there is no movement of the arm on the air mix servo. So I opened it up. Everything looks fine inside but I am the definition of a novice at this. This is my first electrical type repair. I found the part number as 87106-04010 and several sites have them at $180 ish. However, before doing that I'd like to test it to make sure it is the issue rather than some wiring somewhere between the control box and the servo. The directions in the FSM seem understandable but being a novice I am not quite sure exactly HOW to do this test or what tool / equipment I need. Hopefully something I can pick up at HF. Do I do this test using the vehicle's battery? One wire between positive post and #5 pin and one wire between negative post and #4 pin? If that's the case I need some instruction on exactly HOW to accomplish this. Are there some special leads that have clamps on one end and a "pick" on the other so that I can clamp to the battery and then touch the 4 or 5 pin? I Googled and looked at HF site and didn't see anything like that. Appreciate any help.

 

All you need is a set of multimeter leads really. Just stick the pointy ends in the corresponding pin holes, and touch the other ends onto any 12 volt source, the battery will work fine.

 

So these should work huh? Probably need another pair of hands to help hold stuff.

 

Yeah they should, you could use aligator clips to hold the other ends on the battery. The pointy ends may be a tad too big, but its worth a shot.

 

Get something like this for best results

$15 Lisle 65150 Flexible Back Probes

https://www.amazon.com/Lisle-65150-...ocphy=9032504&hvtargid=pla-569984892851&psc=1

 

If the cable is frozen, just order a new one. PB Blaster, WD40, silicone spray, nothing will work. I tried that with the cable in my 99 and it was toast. Order a new one in advance and you'll be happy you did.

 

OK.... I don't know I would use those. Would I need something else as well? Like 2 pcs of wire to go between them?

 

Yeah you may need a banana jumper cable to take you between those and your meter

 

Tested the servomotor per the FSM and it doesn't work. Have a replacement on the way from a part out.

With the cable disconnected at the servo and at the heater control valve it moves easily.

Once the new servomotor arrives should be able to just install it and my heat issues should be behind me.

 

And there was heat.... And the people rejoiced...

Just to update and close this, tested and installed the new to me servo, reconnected the cable to the heater control valve, put the dash back together and went for a drive to get up to temperature. Crossed my fingers and turned on the heat and it worked. Went through all the speeds and functions and aside from a pretty good whistle at high speed everything worked as it is supposed to. Less than $200 for a used control box (which I probably didn't need) and a used servo plus several hours of my time and I got done what 2 different shops told me would be in the $1000 range just to diagnose. Thanks to everyone who contributed.

 

This is why I love my power probe. Comes in real handy especially when testing components like this. Also is faster at detecting power and ground wires.