Hello-

I want to replace the power lock on the rear hatch of my wagon. I found one for sale from a '92. Will it work? Thanks.

Oh, and one more thing...........

If it's in the tailgate, I bet a cold one the problem's the tailgate harness and not the motor.

Do you have problems with any other tailgate electric components? The third brakelight, wiper, defroster, license plate lights?

Hello everyone-

Thanks for the suggestions. When I bought the car about 2.5 years ago (from dealer), they replaced the hinges and harness in the rear hatch, so it's a pretty safe bet that it's not that. Everything works in the rear hatch. Lights, wiper, even the squirter!! One day I loaded the car up for a long trip home, had one last thing to put in the back, and the hatch wouldn't open. I know now that the lock quit working in the locked position, but I didn't know that a while ago, so I had a mechanic disconnect it. I found one on e-bay for $15, but I will check out the lock first, then go to the u-pull-it if need be. Thanks for all your help.

It's about time I "hatch" a plan to fix this problem. I'm tired of being "locked out" of the world of functioning devices. The "key" to doing it yourself "hinges" on self-education!

(Sorry, that's for Don)

"(Sorry, that's for Don)"

Oh. Were those puns? Well, I guess we all gotta start somewhere....

And as you said, one good turn deserves another. Can't tumble to that one?

If you can open the tailgate, remove the lock actuator and find out what's wrong. Those things are almost trouble-free -- they're only a simple DC motor driving a pinion 'n rack. Check the thermistor thingy I mentioned -- I've had three or four of those give me grief over the years. A simple clean-up and they were good for another 250k miles or 1000 locks, which ever came first.

Also -- before you spend money -- confirm that you actually have power going to that motor when you activate the power locks. Be a shame to buy and install a replacement only to find that something else was the problem.

A few times I've had various linkages pop off the latch mechanism -- you might have the same in your tailgate.

You said the dealer replaced "the harness" in the rear. Your car has one in each hinge, so he should replaced "the harnesses." Both were broken in my '86 245 when I bought it in '96. Since the right hinge is the only one ever needing replacement, the dealer mighta only done the right hinge 'n harness. Dealers are like that.

Both sides were replaced. They still look brand-brand new. I will rip into everything tomorrow. Thanks for all of the help.

"...to replace the power lock on the rear hatch..."

They're the same as in the doors, though you might need to install the mounting bracket on the other side. You can probably scrounge one from a junked 240 fr free. I have a box of 'em from various junked cars.

Why replace it? The only time I saw one of those fail was when someone slammed into the side of a 240, crushing the motor.

Inside the motor is a thermistor -- it's a disc, about the size of a nickle, gripped by metal clips against the flat sides. The flat sides are metal coated (silver, I think), and over the years the silver tarnishes. This creates high resistance, and the motors sometimes become intermittent. By cleaning the thermistor contacts (use a pencil eraser) and retensioning (=bending) the clips, you can restore the motor to operation.

Be aware that the internal rack gear can be installed two ways -- the right way and the wrong way. If installed the wrong way, the door will lock when all others unlock, and vice versa (how do I know that?).

The purpose of this thermistor is to limit current to the motor if you drive down the highway for 100 miles with your arm on the driver's door button.

I can't speak (write) on 240 power locks, but I have some experience on the 700 series. The 700 series uses a different lock motor for the trunk than the doors. The trunk lock motor did not work on the son's 87 744T when we bought it a year ago. I took the lock motor apart and found that one motor lead had come off the copper tab it was soldered to. I did little of the famous Don Foster re-soldering at no risk and no expense, and the trunk lock has worked just fine since.

yes, but if it costs more than $10, you're getting ripped off.

these are about $0.10/12 (dime a dozen)