First Honda Accord Repair: Heater Switch

I completed my first repair on the Honda today. Although I suspect it may be--as most of the repairs may be, here at the bottom of the learning curve--a rather temporary thing. But that's okay!

I reached into the machine, and I made things better. Also, nothing broke.

A few days after we bought the car, I discovered that the heat control knob spins rather uselessly in the dash, apparently connected to nothing. This is no problem for the summer. I hadn't really expected air-conditioning to work in a 17 year old car, and we've got a few months to go before I have to start worrying about the cold again. But this just felt like the right sized challenge for ignorant and eager little me.

The Haynes manual instructed that the knob could be removed by gently prying at it with a small screwdriver. Well, actually this one lifted out with no effort at all! The back of the knob, which was meant to fit around a post and grip it firmly, was cracked and broken--half of it was missing. Faithless plastic! The post, however, was metal. I tried turning it with pliers to see if that would adjust the heat.

But it wouldn’t turn. At least, not more than a hair, before springing back. Also, it was clear from the deformation and scoring on this post that I was not the first one to attempt to turn it with pliers. Rather than force it, I returned to my Haynes manual. It had instructions for disassembling the dashboard and getting at the cables, but nothing about this particular problem. So I went to YouTube.

Aha! A video where the heating control valve and cable are described! I rushed underneath the hood of my car to lubricate the valve, stymied for several minutes by the awkwardness of navigating a bottle of three-in-one oil around my air intake to the base of my firewall. Once I got that all greased up, I reached down to open and close it manually. It moved, but stiffly. I thought, worse comes to worst, I can always turn the heat on from out here. And with this much resistance, a replacement knob would just crack under the strain. I was thinking I might need to replace the heater valve, which would mean moving a bunch of these other hoses and tubes out of the way and then hoping I could get them all back together again.

Then I thought, maybe it's not the valve that's stuck at all. Disconnecting the cable was easy, just a matter of lifting it off a post. And indeed, the valve opened and closed easily now.  It was the cable binding up, somewhere along its route. I had visions of disassembling the dashboard to trace it out, looking for signs of kinks and chafing. But as I worried it back and forth, things seemed to loosen up somewhat. The wife sat in the car and confirmed that the dial was moving at the other end. Just moving the cable back and forth for a few minutes seemed to make a world of difference.

I’ve ordered a replacement dial, but in the mean-time I’ve discovered I can take the identical dial off the fan selector switch and place it on the heater post. It works! The control doesn’t seem to be accurately calibrated, but I do have a decent range of hot to cold air to choose from until I want to pull off that dashboard someday and see what’s really going on in there.