Hello, and thank you for choosing Just Answer to help you with your questions!
Just becuase you do not have the power liftgate does not mean that a dead bettery won't affect it. Even though it is a manual liftgate, the little black rubber thing (the "handle") is actually a little microswitch that triggers the motor in the latch itself to release when you press the button in the handle
First thing I would check, which is *VERY* common down here in florida at least (and I would assume other "warm weather states") is the black rubber part tends to melt, and make it incredibly difficult to get the button to press to activate the latch.
They also make quite a mess
There is also a possibility that the microswitch inside there just isn't working anymore. To check this for sure you would need to remove the inside door panel. There will be 2 wires coming from this switch, a red and a black. tiny wires. Basically you will want to use a paper clip or soemthing and short these two wires together for a second and see if you can hear the motor inside the latch move.
If so, it's a bad switch and should be replaced. Should be about $60 at the dealer
If that does nothing, then it could be a latch, or a number of other things. I would recommend the dealer here, as they can plug a computer into the car and read a lot of data and see exactly what is going on
I live in michigan so the rubber is still in pretty good shape. I think the microswitch is working because the switch works sometimes.
I tried the deal the electrical test ($50) the electrical test didn't show anything
It is possible for the microswitch to work intermittantly. Basically you're going to have to get the vehicle in a failed state, and try jumping the red and black wires at the switch together and see if it triggers the latch
When you say the outside panel doesn't seem to "give" at all, by outside panel are you referring to the black rubber cover that you press on to open the hatch?
If so, then I would definitely replace the back door opener switch. It should have a noticeable amount of "squish" to it