Dear Car Talk:

I have a 2007 Toyota 4Runner. Two or three years ago, the blower went out. I called my service advisor at the Toyota place and asked what I should check before I brought it in. He said, "Reach under the dash on the passenger side and give the blower motor cover a hard whack." I did, and it started right up. This happened a couple more times, so I took to carrying a persimmon shillelagh in the car to whack the thing with whenever it failed to work. It worked like a charm every time.

Eventually, the problem disappeared. No problem for two or three years -- until today, when I got back into the vehicle at the grocery store. It was 104 outside, and the AC wouldn't blow. So I whack the sucker with my hand and, bingo, it comes on! So what gives? Do I continue whacking it until it no longer responds? Or do I go ahead and get a new blower motor now? I still have the persimmon shillelagh.

-- Dale

Well, you can keep whacking it if you want to. The reason that works is that when an electric motor fails, it's often because there's a bad connection, or the brushes are worn out and not making good contact. And giving it a physical jolt often can get it moving again, and then momentum takes over.

But eventually, whacking it will stop working. And you know as well as I do that it'll be 114 degrees out the day that happens.

So my advice would be to just go ahead and replace it. You know it's going to fail permanently at some point -- why not replace it now and never have to worry about it again? Or, if you're really curious about how long you can go on like this, at least buy the motor and keep it in the car, along with a set of socket wrenches. You probably can get a new blower motor for less than 100 bucks. And then, when that day comes and the shillelagh doesn't work, you'll be ready. "

The blower is just held in place by three screws. You'll have to pull it out, unplug it and swap out the fan itself, which is attached to the shaft of the blower motor. Then you replace the screws, plug it back in, and you're good to go.

Of course, you'll be doing this under the dashboard, with your head upside down in 114-degree weather, Dale. So, like I said, I'd just do it now.