I'm somewhat good with wrenching on my LR4 but know very little about diagnosing electrical issues. The upper rear hatch on my car does not release from the rubber button above the license plate frame nor does it release from the FOB. I ordered a replacement actuator and plugged it in to see if that was the issue.I did not install it, only plugged it in. It would still not actuate from the rubber button. I got my multimeter out and tested the following. First, I unplugged the rubber switch. I found 12 v on all the males pins. Then I tested the plug that goes into the actuator. I only got a 187 mv, or millivolts I believe.
I've got a new rubber switch coming tomorrow, but in the meantime, I'm trying to figure out if there should have been 12 v at the plug for the actuator or does the rubber switch, when working, allow the 12v to pass on thru and head downstream to the actuator. Sorry for the lack of proper terminology!​​​​​​​

 

Wanted to further update that I found 12v on two of the pins as shown but still can't actuate anything with a new switch and and new actuator. On my LR4 ( its my wife's LR4 that is having the trouble) I ran a test on the same two pins. Oddly enough, with the multimeter in continuity mode, when I touched the two pins it triggered my upper tailgate actuator.

Can anyone comment about some sort of code being stored the shuts the system down when an actuator has been going out for some time? I read about a code that can be stored that protects the system.

The attach picture is the piece that gets pushed on to the wires from the rubber switch.

 

Sometimes a code will set that shuts the circuit down (on the ground side). Check for obd codes. write them down, then clear the codes. i assume you don’t have a gap tool. cheap obd scanner might be enough, but not sure.

 

I went to a local indy guy today and he use an Icarsoft tool VR2 to scan for codes. None were found. Does these scanners check the body control module? Thats were Ive read about a protection code being stored.

I also did the battery reset and no change.

So with the switch replaced and the actuator, I still don't have a fix. Poking the pins with my multimeter, I can find 12v but don't know how to test any of the pins for ground faults that I've read could be another issue.

With the previous picture above, both my cars showed 12v. On my rover, bridging the two pins, triggered the actuator. On my wife's car, the one that is not working, bridging the two pins caused fuse number 25 to burn up. That fuse controls the drivers side taillights and the power to the clear lights above the license plate frame.

Not sure if this I related but my wife recentlyinformed me that the passenger side carpet was wet. Drain tube was off and there was a fair amount of water in the channel that runs along the edge of the car, underneath where the door close, where that was a large bundle of wires. I removed the water and dried it all out. The angled carpet was not wet so I dont think the BCM got wet.

 

Just took a look at the wiring diagram (attached). Looks like depressing the tailgate switch completes a circuit to the BCM, which then sends a signal to a FET that sends 12v to the tailgate release solenoid. It also looks like the switch circuit has a connector in that passenger side A post area, right about where the sunroof drain leak happens.

 

Update.....Problem solved! The tech that scanned the car yesterday withth Icarsoft reader didn't find any codes. I went back again today and the head tech used the SSD factory computer and found the ode I had heard about. B12EE was logged in the BCM and shorted the whole system . He cleared the code and right away the actuator was working again! Thanks for helping out!