I think my AC fan needs an exorcist.

Those steering-wheel control signals go through the "spiral cable" (a/k/a "clockspring") behind the steering wheel, which is a wear item, because you're continually turning the wheel. When it gets worn, you can have those controls not work reliably, and/or also send spurious signals when you're not trying. (The horn signal also goes through it; some people let the spiral cable wear out all the way to the point of "horn honks every time I turn left" forum questions, and somehow are not embarrassed by that. )

So that's a place I'd look.

 

Knowing to be cautious is good, but do you also know how to be cautious with an airbag?

That is, how to be sure the deployment reserve energy is drained from the system before you start, how to handle the bag/pad and what way to set it down, any time you set it down (and why that way)?

All in the manual, but should also be in plenty of threads around here.

Not many other booby traps I can think off. Make sure you're putting a centered spiral cable onto a centered steering shaft, and that you marked the wheel and shaft before pulling the wheel so you can put it back on pointing the same way.

The shaft end, and the bore in the steering wheel, are splined. The splines are very fine (so there are lots of choices for aligning the wheel), which also means they're very shallow. Turning the wheel at all while reinstalling it could grind 'em right out. It's a very light touch; you ideally want to feel that you've got the wheel lined up just the way it was, you can very lightly tell that it's dropping right into the splines the way it was before, drop it lightly the rest of the way and hold it there steady while you tighten the nut.

Torque wrench, of course. Auto parts stores often let you borrow the puller to get it loose straight off the shaft, again with no wobbling on the splines as you might by trying to just yank/pound it off. M8x1.25 bolts in the puller to mate with the tapped holes in the wheel.

 

Dealer prices are all over the map: sometimes you expect something to be cheap and it's an arm and a leg, sometimes you cross the dealer right off your list because you're assuming a part will be super expensive and it turns out the exact part at the dealer is like $12. So it's always worth checking.

I agree they are proud of their spiral cables. But reports of people trying way-cheaper ones from ebay or wherever sometimes seem to end with replacing them again pretty soon.

A steering wheel puller looks like a skinny H. The wheel has two M8x1.25 tapped holes in it, diametrically opposed across the shaft. You get some longish M8x1.25 bolts and slip them down through the slot of the H at both ends, and then the puller bolt in the center bears against the steering shaft.

The puller may not actually come with the bolts you need (or may come with a selection of different threaded bolts) because not every manufacturer taps the wheel with the same size or thread.

You've probably found it already, but just for reinforcement, always set it down with the metal inflator housing down and the pad up. If anything sets it off, it sits there and the bag blows out the top.

Set it down the other way, and any deployment blows the bag out the bottom and launches a kg of steel into the air at you. Hard.

 

Did the replaced clock spring fix your problem?
Thanks for the other feedback.

 

If you haven't done a HID headlight bulb there is a bit of a learning curve to it especially on the drivers side. If the bulb doesn't fix it the ballast for the light lives in the bottom of the headlight assembly, they don't like water. I have done the license plate light bulb too and it seems like a big deal removing that big plastic cover but once you pull it, it is a piece of cake. I replaced my license plate light with LED bulbs hoping they would be better at taking the abuse of slamming the lid.

Does your headlight look wet inside?

 

If you own it long enough you will get good at changing HID bulbs and removing the headlight assembly. I think I had it down to about 10 minutes. Kind of like the tire change scene on the movie, "A Christmas Story".

 

I didn't use any special skill or logic, when a new HID bulb didn't fix it I went straight to the ballast. When I found the ballast swimming in water I changed it. While the headlight was out to replace the ballast I used hot glue to reseal the headlight to keep the water out and it worked.

 

I had a glue gun for my model airplanes and you can see the seam, just something I tried and it worked. You may not have that problem.

Toyota Prius: How to Replace the HID Ballast/Computer/ECU - PriusDIY.com