Can someone explain what the purpose of the rear hatch contact plate does on an 89 TA?
I have been having issues with the rear hatch lift motor assembly and have tested all of the components and all seem to be working after replacing a broken motor housing and stripped gear, but it does not seem that I can bench test it correctly before putting it all back in the track assembly, it goes in one direction, down, but can't seem to make it switch to go back up.
The striker switch seems to work and the wires to the motor switch do reverse polarity, and the switch mounted to the motor gets flipped accordingly and shuts motor off like it should....
Only missing component is the hatch is not really closed so I tried grounding the 2 contact patch areas together as if the hatch is closed but has zero affect.

Looks like the striker switch controls the light on/off and the reversing the ground wires to the 2nd or 3rd pin on the 4-wire white plug to the motor switch based on it being open or closed.
The motor switch is responsible for reversing the polarity on the motor.
What does the contact plate being closed (hatch down contacting plate) control ??

 

Most cars,... just the rear brake light,. Some 82-86 cars also used if for the rear wiper.

 

Ah, didn't think of that. Both posts on the contact switch ground to each other so thought it just created a closed circuit for something, has a black and yellow/black wire connected on the pad side. If just for the brake light, what is the function of having 2 wires combine together on each side of the switch?

 

1 wire is power ( Yellow/Black ) and the other is ground (Black).

They should not be touching each other in any way. If the black wire feeding the contact pad is touching more than 1 "finger" than ground is supplied for an option that you do not have installed. Schematic is for an 88 Trans Am.

 

Ah, Thank you sir! My bone head just did a continuity test on the 2 posts on the hatch side of the switch and thought it just connected the 2 plates on the pad to signal the hatch was up or down for something....so of course with a bulb in the 3rd light it would have continuity between both posts.

Ok, so I can take that out of the equation with the lift motor functioning....gotta be just where I had the motor switch positioned between the 2 tabs that flip it up and down.

Thanks