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I've got a 2005 Acura TL (base model w/o navigation) and have an A/C problem. I first noticed that the cabin wouldn't cool off (spring time in Texas). Then I noticed that the air really wasn't coming out of the 2 center vents, but it really felt like it was coming out of the dash. Air does blow out of the driver & passenger "door" vents. I disabled "auto" and tried to change the modes (air flow direction), but nothing changed on either the driver or passenger sides (dual off or on). I got my hands on a copy of the service manual and ran the self diagnostic a few times, each time it came back with the O code (an open or short in the driver's mode control motor circuit). I removed the actuator/motor and the door mechanism seems to move freely. I put a voltmeter on pins 1 & 2 of the 10P harness and I do get a reading (for 2-3 seconds) when I press the mode button. I also took the actuator apart and none of the gears seem to be missing any teeth and the gears move freely.
Is there anything else I should check/try before I get a replacement actuator/motor? Do my symptoms seem to match the problem as I've diagnosed it so far? I ask because it seemed odd that a driver side motor would also prevent mode changes on the passenger side while in dual mode, but I've not gotten any codes for the passenger side. As for it not blowing cold, it could just need a recharge ... it is a 12 year old car.
I took the actuator apart breaking every clip, but it still fits together so tightly I'm not worried about it. I removed the gears in the following order:
The last gear is attached to the actuator arm on the back side (not visible in the picture), but they are 2 pieces and can be pulled apart.
On the other side of the large gear are metal contact "fingers", which were corroded and both they and the circuit board were covered in gear grease. I removed most of the grease from where it didn't belong, used a piece of sand paper to clean up the contact points of the fingers, and wiped everything clean with q-tips and fingernail polish remover (didn't have any isopropyl alcohol).
After making sure everything was dry I put it back together, plugged it into the harness, and the actuator arm now moves again when pressing the Mode button.
Nice writeup and pictures! Let us know how it goes.
IMO I would have (silicone) greased the gears and also lightly greased the contacts. Gears for the usual reason and contacts to avoid wiping wear and reject moisture. Shin-Etsu silicone grease (every Honda/Acura owner needs a tube) would have been my choice. It's safe on plastic unlike many others. But if you have put it all together already then leave well enough alone I'd say.
Nice write up!! I haven't had to do this to my HVAC controls...yet...but I found similar issues with the contacts on my mirrors. Also to note...for anyone else attempting this, I would highly recommend proper electronic contact cleaner. I would be concerned with more powerful solvents eating things you don't want it to. Modern nail polish remover is no where as bad it previously was...but still probably a tad harsher than optimal.
Pretty sure I have a can of CRC 5101...I need to go out to the garage to confirm. It is what I used when attempting to restore a 70's RCA cabinet stereo, my TL mirrors, and any of my kid's toys that has leaky battery residue.
It's all back together and working great. That thing looked like it had been packed in grease, there was plenty left over to grease up the gears and moving parts.
As for the finger nail polish ... I know it's not ideal, but was the only thing I could find and was careful about what it actually touched. I made sure it was dry and then went back over everything with a clean/dry q-tip as well to clean up any potential residue. On the contacts, I have some dielectric grease, but since the contacts move all around I was concerned the grease may ultimately cause a short.
Thanks for the tips and the additional garage supplies ideas. Now it's back to researching getting the air cold like it used to be and the 105K service DIY's.
Great pictures! My mode selection works fine but I had issues with temperature control a couple years back. I took out/apart the air mix motors and it was the same issue. The electrical contacts were caked in grease. I cleaned everything up and it worked again as it should. Before I'd have to crank it to 'Hi' before any heat came. Seems like Honda was just very generous with the grease and over the years it builds up on the contacts. It's such a simple fix, it's worth trying before replacing.
04-03-2017, 02:38 PM
