rushw

Quick background: I recently changed out my oxygen sensors on my 2002 Toyota Highlander V6. I got the difficult to reach one at the rear of the engine out by myself. However, the front one under the engine manifold proved impossible, as it had heat fused to the manifold. There was no other way aside from removal of the manifold it could be freed. I took it to Midas - who advised that a new manifold would have to be obtained and installed (which they got OEM from Toyota).

THE PROBLEM: I picked up the vehicle yesterday evening. The repair job looks fine, however I noticed that the clock was acting funny, showing 1:00 each time I started the ignition. Then it completely shut off this evening when I drove home at rush hour. That and the heating control unit. The clock is dark and the heater control unit illumination will not light. The HCU air temperature selector knob (cool to warm air) works, the intensity (low to high) knob works, the problem is in the air directional knob. It is now only blowing air from the windshield vents, not through the ones aimed towards head, feet or both of those.

Radio still works, as does dome light and door panel lights. I checked the fuse box and replaced the 7.5 fuse associated with the clock. No change.

What else might be wrong here? The battery connections are tight. Midas rechecked their work, finding everything was plugged in correctly and the fuses were okay. Just thought I'd ask here before going to Toyota for a fishing expedition.

Thanks!


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brian2sun

Take it to Toyota and when they find out that Midas screwed the pooch, take the bill back to them.

rushw

I just took the heating control unit out and looked inside the HCU. All the switching cables appeared to be intact. The temperature control knob and air flow control knob were still functional.

It is the problem with the air directional flow knob that is the non-responsive one. It occurred to me as I was unplugging the 3 plugs that connect into the back of the HCU that perhaps the one bank closest to the air directional flow knob might have a short or something like that in it's wiring. If that were the case, could that possibly explain why the a/c light, recirculate air light and rear windshield defroster light went out, due to having only 2 of 3 cables in that array in working order?

I cleaned all of the plug ends with auto electronics safe spray cleaner. Going to put everything back in place now and see if any creative responses arise here before going down to Toyota.

Thanks!

rushw

I went to Toyota today to have them solely determine whether the fault was in the heater head unit or wiring that supplied it. Wiring is fine, head unit is just fried. I declined their offer to install a replacement for $700 plus labor. Instead, I bought one from eBay that has been restored and reinforced for almost 70% less. Installation will be easy for me to do- thank goodness for sites like these with photos of how to get in and work on such parts.