Sporadic heat this winter (Freeze to death commute)

Your 22 code does indicate slippage of either the A/C clutch or the drive belt at some point (whenever the code was logged). It probably won't have much to do with your heat issue though. If you're sure there's not a clutch problem you might check the condition and tension of the belt (sometime between now and the next hot weather).

You haven't said much about what your heat issue is, though. Does the blower not blow air? Does it blow air that isn't warm? Does it blow air out different outlets than you've selected? Do all positions on the blower switch have the expected effect? Does turning the temperature knob change anything? Is your cabin air filter clean?

More information describing the problem => more opportunity to help.

All of the information on wiring, relay, and control unit locations and test procedures you can find in your service manual and wiring diagram manual at techinfo.toyota.com. $15 gets you two days of access (which you can also use for downloading whatever is of interest so you can refer to it later).

-Chap

 

Our NHW11 still has a mechanical valve system ducting air through the heater and air conditioner cores. It is entirely possible that the mechanical linkage, one in particular, might be having trouble, as I had it fall off and that caused a lot of grief.

On the driver side above and towards the seat relative to the accelerator, there is plastic link that controls the air-valve settings. Changing an accelerator out (something I used to do often,) I once knocked the plastic linkage off and didn't put it back on right away. We had this dog and . . . . Long story short, I lost heat and air conditioning until I got a replacement linkage from a salvage yard and thanks to Murphy's Law found the dog chewed part. I put it back on and a miracle occurred . . . heat and cold air!

I'll check my archives as I thought I'd taken some photos of the linkage, a milky white, plastic linkage about 6" long with an offset in the middle and slot on one end. Not quite flimsy, a clumsy person fiddling in the accelerator area could knock it off or akimbo.

Bob Wilson

 

The 22 is a clutch problem, but that won't matter until it's air-conditioning weather again (ok, maybe that's too optimistic, because the defrost setting also won't work as well with compressor slip). But you've got a bunch of other things going on. Honestly, with this list of things I'm surprised 22 is your only code. Did that come from you recently reading the codes yourself? If not, you might want to do so, and be sure you note down all codes being blinked out until it loops around to the same numbers again.

If the air outlet selection isn't matching what you select, the next step might to note down in detail which outlets are getting air with which settings on the dial. Checking that against the heater airflow diagrams in the New Car Features Manual may give you an idea which doors or servos are at fault.

Does the fan run quietly without vibration? My Dad had mice build a nest in the blower wheel of his car, detected when the fan was turned on and nearly shook the dash off the car.

The heater is kind of a "hybrid" itself; most of the heat (5300 watts worth) comes from hot liquid through the heater core like any other car, but there is also a small ~300 watts worth of electric heat built in for extra comfort before the fluid is hot. I don't think any of that was likely to be damaged by something getting through the cabin filter though. The electric elements are partly built into the heater core and partly located in the footwell outlet duct (warm-climate cars lack the ones in the duct).

-Chap

 

If something tore a hole through your cabin filter, the most likely cause of that is a rodent. Rodents are known to inhabit the heating system of a car. Nothing else could cause a hole in the cabin filter. This is also the likely reason for your problem of sporadic heat.

 

Don't forget to check the radiator fluid level (main gas engine radiator)...without a full cooling system you will not get adequate heat...on any car....this sounds simple but a lot of people overlook this.

 

What about a sporadic heater fan? I've had a 2006 for the past year and a half, and sometimes the heater fan works, and sometimes it doesn't. Sometimes it comes on immediately, sometimes it comes on after 30 minutes, sometimes never. Typical winter temps in this part of Idaho are mid-20s overnight to mid-30s daytime. The A/C works fine in the summer.

Any guidance would be greatly appreciated.

Todd

 

If your temperature dial is not changing anything temp wise, check the connections in the back and try it again, if still nothing, that could be your culprit. if you can get the dial apart, maybe you can clean it up inside and it may work again, if not, look on ebay for one. or maybe someone here has a way to test the wiring to make sure all the servos work correctly.

 

This is the Gen 1 forum so I don't know specifically about your 2006, but my Gen 1 has an auto fan setting as well as manual low, medium, and high settings. Does the 2006 have something similar? Are you just describing what happens when the unit is operating on auto, or have you tried the manual fan speed settings and also had the fan not come on, or come on with a delay?

Characters in the action: you've got the blower itself, the electrical connections to it, the ECU board controlling heat (in the Gen 1 it sticks out behind the center control panel and isn't much fun to get to, I don't know the 2006 location), and also an electronic fan "resistor" mounted on the fan housing (where a real resistor used to go in other cars). Contributor hobbit has described that part nicely (and was describing a Gen 2, so it's the description for what you've got).

There was also a post here a few years back from somebody with a Gen 2 where the electrical connector to the fan itself overheated and failed. It's a two-pole connector with fairly heavy wires, and if I remember right the shell was a natural nylon color except for the cooked spot. That was a pretty simple fix and the symptoms were similar.

If you don't have the wiring diagram you can view it at techinfo.toyota.com (there's a small subscription fee). It will show you what's connected to what and where all the pieces are located, which can save you a bunch of experimentation (as Frank Westheimer observed, "A couple of months in the laboratory can frequently save a couple of hours in the library.").

-Chap

 

DO you have a voltmeter? if so, see if your even getting power to the fan when you turn it on. if not then start tracing wires and checking relays. just go to your relays and tap the one for your fan/ heater/ a/c. if it comes to life, replace that relay. it could possibly be as simple as that.