Liftgate won't lock--any help/advice is appreciated!

I recently purchased a used 2005 Acura MDX that I love, except for one perplexing problem: The rear liftgate will not lock. I’ve tried using both the remote and the driver’s side lock buttons with no luck–all passenger doors lock/unlock properly, but the trunk just won’t. When you press the remote’s lock button, you can hear the liftgate door “clicking” in response, as though it were locking, but it doesn’t actually lock. I suspected a bad actuator and brought it in to the dealer, and the technician insisted that the problem couldn’t be the actuator because he could hear it working. Does that sound right? He wanted to charge me several hundred dollars to take off the door panels and poke around. Is there another thing that could be causing this problem? I need to get this fixed ASAP. Thanks for any advice you can give.

Well, I would probably start by just getting blowing the thing out with a cleaner - probably with some electronics cleaner b/c it leaves no residue and will be gentle on plastics and paint. After blowing some cleaner through the whole mechanism I’d spray whatever lubricant is recommended up there. (Something grease-like as in white lithium spray or something. No WD-40).

If that doesn’t help than it is likely that the panel does have to come off. A $20 repair manual from an auto parts store will give you the steps for doing that if you’re feeling ambitious.

If you don’t want to try DIY, find a good independent body shop. They should be able to give you an estimate that beats the dealer estimate. A body shop deals with many issues like this daily, and usually can provide cheaper, quality results.