I have an 02 4Runner with manual climate control. I initially thought I had a problem with my AC system because of the intermittent cooling. Now that the temps have dropped to the 30s, the heat is doing the same thing. It works intermittently.

After the engine is warmed up, the heat may work fine and then suddenly start blowing cool air. If I cycle the temp control knob from hot to cool and back a couple of times it will normally blow warm air again. This is exactly the same thing that was happening with the air conditioning. It would blow cold air and then start blowing hot air out. If I cycled the temp control knob it eventually blows cold air again.

I am guessing the controller itself is going bad but wanted to get everyone’s thoughts on it before buying a replacement. Is there anything else that could cause the problem? If I replaced the controller, is there a good alternative other than oem?

3 ways that come to mind:

1. Send it to one of the folks on the forum that do repairs (the control unit's circuit board oxidizes and the knobs do crazy things - happens to many people eventually). I had mine done for $75 and had new alt-color LEDs installed for another $10. Been working great for a year or maybe 2.

2. Search this forum and read the excellent tutorial someone here did. If you can solder with any precision, you can repair the connections yourself.

3.Roll the dice on a salvage yard or eBay unit.

Speaking of eBay - there are repair shops that do this there too, but are much more $ than the gentleman on T4R.ORG who did mine and others.

I was thinking that it was the automatic climate units that people were having repaired. I didn’t know the manual units had the same issues. Would you share the member’s name who repaired your unit?

Yes, I googled up one of the threads here on T4R. I was doing some yakking about this service on the last couple pages linked below. I have a 2000 and did not know there were other versions of the climate unit. I would guess they suffer a similar fate, if so.

Auto Climate Control Repair Services

Here is John's contact info: (better to email him directly rather than through his account on this forum)

"Please send me an email to [email protected] and I'll get you fixed up. 2000+ Controls repaired as of this date."