i replaced the hatch motor in my 1991 GTA but it still doesn't work.. it has power and power is present when checked. Any ideas?>

 

If you replaced the motor and it still doesn't work it may be one if not both of the electrical switches on the pull down assembly.
Latched/unlatched switch tell's the system if the hatch is open or closed
Reversing switch, when the motor reaches the bottom of it's travel it flips a switch so the the motor will will be reversed and travel the opposite direction to open the hatch.
There a number things that can go wrong
You replaced it with a new motor?
Does the hatch release work at the dash?
Did you check the ACC fuse? Have continuity across the fuse, sometimes a fuse can look good at a glance.
Do you have 12 volts at the red/black wire at the relay?
Where is the motor sitting, up or down?
Any activity when you push down on the latched/unlatched switch?
Any activity when you push up or down on the reversing switch?
Condition of your ground wire next to the pull down assembly, do you have continuity to ground?
Have you checked to see if the extend relay is good?

 

the hatch does release from inside the car when the button is pushed. When trying to close it latches but the motor doesn't engage to pull the lid down. There is power there.. the voltage number i cannot remember. I changed the motor myself at the time.

 

Which style of pull down motor do you have, 91 mid model year GM changed the pull down assembly almost completely, not sure if any part are interchangeable. The 87-91 (early to mid year) style will have a metal frame and the 91 (mid to late) & 92 have a fiberglass type of frame.

 

i have the basic pull down motor not the mid year change.

 

Is the mechanism in the down position?

 

FYI it is almost always the blue grease in the gearbox on the bottom of the unit. it hardens up from age. and the reversing switch in the middle of the mechanism. the rev switch cant handle the additional load of the thickening blue grease and usually ruins the contacts in the switch.1) take the reversing switch out and spray with CRC electrical contact cleaner, while flipping the switch back and forth.....spray the switch several times.....2) clean all, and I mean ALL THE BLUE GREASE out of the gearbox drive for the pulldown. re-pack the gearbox with high quality, hi temp wheel bearing grease. I own 3 of these 3rd gen camaros and just fixed all of them using this method. the original pulldown had the motor and gearbox removed before I got the car. original repair was 2 large tek screws though the sliding tracks. I got a pulldown unit from craigslist and rebuilt it the same way.....works perfectly!!!

 

very good point about the factory grease, I just recently rebuilt mine and after 30 years it pretty much was the consistency of clay.
OP’s case maybe the unit was mechanically binding because of the grease or another part failure because of the “grease”
Still like to hear what OP says about the assembly’s current state.

 

im gonna check when i go out later today if all goes well but im pretty sure its in the down position. I will take a few pics of the area when i go out.. i didn't even consider the grease aspect, something for me to check out for sure.

 

The guides can also cause a binding issue leading to extra torque to the entire system which leads to the motor housing cracking and gear nut, electrical components getting hotter than they can handle in the long term, the whole mechanical assembly and electrical circuits are more complicated than it needs to be.
If there is a humming or buzzing coming from the assembly or the motor is turning but no going UP it’s more of a mechanical issue IE the guides/grease situation.
If there is no electrical activity like humming or buzzing like an electro mechanical devise is trying to operate, if all is quiet it’s more than likely the reversing switch contacts are dirty/corroded/burnt to the point there is no continuity on the UP circuit. When I was troubleshooting the electrical circuits it came down to my reversing switches UP contacts were dirty and corroded, there two brass rivets that need to be drilled out and one very small Torque bit screw, a T4 I think, to disassemble. Once your in there you can assess where the problem contacts are, I used some 1000 grit sandpaper to clean mine.

 

here is some images. Car is currently is storage and I'm hoping to move her out tomorrow where i can work at the Hatch.

 

Looks like it’s in the up position, assuming you have 12v going to the system when pushing down on the switch circled in red the whole assembly should immediately start its travel down, now that’s contingent on if the assembly isn’t in a severe bind mechanically.
Speaking of mechanical bind, 30 year old OEM grease I feel is the main issue with the pull down assemblies, at this point the OEM grease has the consistency of Play dough or clay, if everything was working and you had no issues it still would be a good idea to completely disassemble the pull down assembly to clean the OEM grease out and re-lubricate, I used Lithium grease, but anything is going to be better than what’s in the now.
Mechanical bind, I can see there appears to be at least two guides intact but what you can’t see could be totally broken up, if your disassembling the unit these should also be replaced