2010 Mountaineer Liftgate Won't Lock - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

kwaskow · 11-24-2012, 15:10

My 2010 Mountaineer Premier V8 liftgate won't lock. Tried with Fob and keypad. All other locks work fine, including the liftgate glass.

**360ci** · 11-24-2012, 18:35

Do you hear the lock motor (actuator) in the rear hatch trying to function? If not, check all fuses and other connections under the hood. If everything is tight, electrical shorts are the worst to find. Most of the time its due to corroded connectors. I would start by pulling the rear panel off and making sure things look OK, even get a voltmeter and test the leads. If you can, try putting a load to the actuator for one second (so as not to burn it out) to see if it will function after disconnecting the wires.

If you hear it, it could be a couple of things. The first, is the actuator is on its way out - its not putting out enough torque to lock/unlock the hatch. The second, is that there might be corrosion on the leads (often rivets) that slide a metal or in many cases, a plastic piece, that the actuator pushes/pulls on to lock/unlock the hatch. I had this problem with my Dodge Durango. Moisture got in and corroded a rivet and a small bolt. I was able to replace the bolt, but with the arm being plastic I dared not to drill out the rivet and reinstall another, as I didn't want to crack the plastic arm.

If you can, search around for a Mountaineer FSM (factory service manual) as it should provide you with the proper wiring diagrams.

kwaskow · 11-24-2012, 19:52

Yes it seems to be trying to work, based on sound and vibration in the liftgate, though that could be the glass hatch.

kwaskow · 11-24-2012, 19:53

Curious too, which fuse might be solely assigned to the liftgate lock?

**Bert** · 11-24-2012, 20:11

Fuse #6 but it runs the door locks too. Check what 360ci mentioned.

**360ci** · 11-25-2012, 06:01

As you more than likely need to remove the interior hatch panel anyway, disconnect the glass hatch lock power and see if you can hear anything coming from the hatch motor to know for sure if it's trying to unlock, but cannot. Also with the panel removed you can spray and rusted parts with WD40, or something similar.

I forgot to mention that I did spray the sole rivet in my lock assembly for my Durango. I have to keep doing this every 6 months or the lock will start to stick again because I cannot replace the one rivet without replacing the whole lock assembly. My rear hatch is held on with 4 screws and pops out, your interior panel shouldn't be too hard to remove as most vehicles are built with quantity, instead of quality in mind.

**CatSkinner** · 11-25-2012, 06:39

On a back note: once you're freed via WD40 or some other penetrant, lubricate it with Lithium grease. It comes in a spray form and will hold on much longer than the penetrant.

kwaskow · 12-09-2012, 10:26

quick update, the solenoid was out of position. simple fix

**CatSkinner** · 12-09-2012, 15:42

Nice to hear.