AC/Heat not blowing

[whitedragon551]

Did the passenger side valve cover gasket 2 days ago. In the process I unhooked 2 harnesses over the valve cover and folded to the right to rest out of the way.

The issue is when I start the vehicle and the air is left on it used to start blowing right away. Now it doesnt start blowing right away. I find that changing modes, temperatures, and fan speed does nothing. However it seems that switching the defroster on and off starts it blowing again. Other times I will hit a bump and it will start to blow right away.

Prior to this absolutely no issues what so ever with heat/AC blowing as soon as I turn the vehicle on. It only started after the valve cover gasket was changed.

The harnesses in question are labelled 1 and 2 in my image. Everything else was left connected and folded over to the right of the image onto the intake manifold.



My question is does either of these harnesses directly relate to the AC/Heater control module blowing air?

[Towncivilian]

Follow the diagnostic procedure on page HA-35 of the factory service manual.

[whitedragon551]

Follow the diagnostic procedure on page HA-35 of the factory service manual.

Went through the diagnostic and it says error code 25 after the 2nd or 3rd step. That corresponds to the sunload sensor, which I assume is the small black circle on the dashboard on the passenger side.

My question is how do I go about troubleshooting that issue? Are any of those harnesses related?

[Towncivilian]

I would disconnect both of those harnesses, clean them out with electronic contact cleaner spray, and reconnect them, making sure they are securely connected before pursuing any other troubleshooting. I'm unsure whether the harnesses are related, however.

[whitedragon551]

I would disconnect both of those harnesses, clean them out with electronic contact cleaner spray, and reconnect them, making sure they are securely connected before pursuing any other troubleshooting. I'm unsure whether the harnesses are related, however.

Will do. Purchased some Quick Dissolve electronic cleaner this morning. Will do that after class tonight.

[whitedragon551]

Found out both harnesses are related to the O2 sensors.

I figure since my diagnostic says sunload temp sensor its the one on the dash board. I seems that if the vehicle is warmed up it kicks right on, but if its really cold out and there is condensation on the vehicle it takes a minute. Is this normal or should I replace the sensor?

[Towncivilian]

I don't have a sunload sensor so I'm not sure of the proper operation of it.

Maybe run the self-diagnostic again just to be sure, and if you get the same result, try to follow the sunload sensor circuit diagnosis on page HA-90.

[whitedragon551]

I don't have a sunload sensor so I'm not sure of the proper operation of it.

Maybe run the self-diagnostic again just to be sure, and if you get the same result, try to follow the sunload sensor circuit diagnosis on page HA-90.

I dont think its the sunload sensor.

If I tap the bottom of the dashboard it comes right on. Reproduced the results 3 seperate times today. Its a piece directly under the center left side of the glove box. Not sure whats under there though. Blower motor is to the right. Ill be checking wiring connections tomorrow.

[Towncivilian]

Is it the fan control amplifier you're tapping on (labeled "fan module" in this photo)?

[whitedragon551]

Its the bottom of that black box where the air filters go in. Its the only piece I can reach with the dash board assembled.

[Towncivilian]

Maybe it's the blower motor harness, then? If you wiggle the wires on that harness, does the blower cut in and out?

[whitedragon551]

Maybe it's the blower motor harness, then? If you wiggle the wires on that harness, does the blower cut in and out?

Im going to test it tomorrow morning before work. Any idea what the part number is on that amplifier?

[Towncivilian]

999M1-VP003

[whitedragon551]

999M1-VP003

Thats the cabin air filter.

[Towncivilian]

Oh you're right, damn, I read that blower motor problem thread too quickly. You'll want 27761-70T03.

[Towncivilian]

Hey, did you ever figure this one out?

[whitedragon551]

Hey, did you ever figure this one out?

Figured out it was the resistor. All I had to do was tap the bottom of the black filter box and it would kick right on. Eventually it just started working all by itself every time. Now Im working on getting it running so I can go back to having 2 vehicles again.