How to save $250 when repairing an automatic car door

This morning I finally took our van in to check on a faulty automatic rear door. This has been a problem since mid-November, but I've procastinated -- and endured a month and a half of opening and closing the cargo hatch by hand (ugh, whatever did people do before remote controlled doors?) -- because I was dreading the cost of fixing it. $250? $400? Ugh. Man, it's such a bummer to realize that your once-cool-and-spiffy van is now seven years old, and starting to show signs of its age.

What finally broke down my resistance was just that: a breakdown. Or rather, an almost-breakdown. We were in Reno, and the car refused to start. Luckily, after a couple of frantic tries, it started, and we were able to get home, but a week later the battery was completely dead. We had to buy a new one. We figured the battery had run down because the kids are perpetually leaving the inside lights on, but we decided to have the van checked out to make sure the charger was working properly.

And that's how I found myself at the Toyota Service area, along with about 20 other cars, waiting for service. The place was a mess; no one knew who would be served first and everyone was trying to get their cars in line, so it was one big knot of cars that couldn't be unraveled. Everyone had sour looks on their faces, including me.

Finally, after 20 minutes of waiting, someone came up to me.

Service associate (very cheerfully): How may we help you?

Me (rather nastily): Well, I've been waiting for 20 minutes so I'd love some service!

Him (with a tone of regret/apology): So sorry for the delay, ma'am, what seems to be the problem?

Me (still huffy): I'd like someone to check and see whether this van is charging its battery properly.

Him: Let's turn on the ignition. Okay, alternator indicator light isn't on, which probably means it's working fine. If you like, we could take the car and run it on the blah-di-blah [some tester thingy that I've forgotten the name of] to make sure the alternator is okay, but we'll charge you $85 for the inspection.

Me (taken slightly aback): Oh. Never mind, then. But (and my tone grows accusing once more) there's still this problem with our rear door. The circuitry or the mechanism or something must have broken because this button doesn't work! We have to open and close it by hand.

Him: Okay, let me see. (He peers at a couple of buttons on the dashboard, just above my left knee. He presses one of them.) Try it now.

I press the rear door button on my key.. and the damn thing opens. I look closely at the button on the dashboard. It says "AUTO REAR DOOR", and below it, "ON/OFF".

Me: Oh.

Next time I really must be nicer to people. Or read the instruction manual.