Blue91Z28

Would someone please explain how the hatch pull down works. Some one must have a step by step or if / then procedure about making this thing work. my motor is up. It won't move. what gives?

Blue91Z28

Both fuses are good (acc and lid). The relay near the latch is good. The switch on the top of the latch works. There is power to the light and the "latch area". How car I find out what is not right?

Joe Tag

iTrader: (4)

The lever that works the switch on the latch will sometimes break off and cause this. The motor will "think" the hatch is always open.


Edit: "The switch on the top of the latch works." just saw that sorry.

Blue91Z28

What next? I will sell this pos because of this trunk. It is such a common problem that someone must have figured out how to trouble shoot this thing.

Joe Tag

iTrader: (4)

Try eliminating the possibilities. Test the leads to the motor and see if it is getting power when working the switch. If not, it's the switch, connections or relay. Disconnect the wires to the motor and put power to it reversing polarities. That would eliminate the motor as suspect or binding in the track.

Blue91Z28

Ok. The motor has four wires, white brown blue and black I think, which wires do what and when do they do it? You say the switch may be bad. what switch. there are two in the latch one on the console and two relays, one under the console and one near the latch. haow do I trouble shoot this system in some sort of methodical elimination.

Scorpner

iTrader: (4)

The pdf below was from the TGO tech article page (> Here). You can get parts from the info on the pdf as well.

https://www.thirdgen.org/tech/hatchpulldown.pdf

Blue91Z28

That is all good and well assuming I need parts. I have replaced my motor and housing a couple of years ago. How does this thing work and how do I test it or check it to find out what is or is not working? The problem is not with the weather stripping or the motor to the latch. It might be a relay (which one I don't know) ALTHOUGH I JUST REPLACED THE ONE IN THE BACK TODAY. It might be a switch. It might be some thing else. How do I figure this out. what happens when it works right? Ipop the trunk from the console button. What happens. I close the hatch to the latch switch, what happens. How do I check this thing to find what is good and what is not?

Blue91Z28

I assume that when the trunk is closed (which it will not do) and I pop the release on the console, the electric release opens the trunk which opens the switch on top of the latch, which tells the motor to go up to the top of it's travel and stop. When the lid is closed the switch tells the motor to pull down until the reverse switch activates and the motor stops. how do I check all this stuff to see if it works properly or not.

Blue91Z28

Surely some one has figured this out. PLEASE don't make me reinvent the wheel and figure this out on my own.

Blue91Z28

power comes in on the blue wire... then.... until, then...., then...

Joe Tag

iTrader: (4)

Playing with a spare harness right now but no relay Do you hear the relay clicking when you work the switch on the latch? when you push the lever on the latch switch as if it is closed, the orange wire on the 4 wire connector at the motor should be grounded. When it is in the open position the white should be grounded. The unit the 4 wire connector plugs into is a reverse switch, the motor itself has 2 leads that have polarity reversed on them like a window motor by this switch. Can you read a wiring schematic? Do you have a multimeter?

Joe Tag

iTrader: (4)

if the white and orange connections at the 4 wire connector are working properly, look into the switch and the motor. You will have to take it apart to figure out since the trip lever is worked by the position of the rod that pulls the mech down or pushes it up. Being in the up position right now, brown should have continuity to the blue.

Blue91Z28

Do you hear the relay clicking when you work the switch on the latch? no
Can you read a wiring schematic? Do you have a multimeter? Yes, Yes.
Thank you so much for the pointers. I am on it right now. I will be right back to let you know what I find.

Blue91Z28

Looking at the schematic, I just realize. today I "repaired" the white wire connection in the latch harness. The part that was burnt had a diode in it. I cut that out and spliced the white wires together without the diode. how will that effect the motor operation?

Joe Tag

iTrader: (4)

pretty sure that's to prevent feedback making the hacth light come on. Playoffs are on so replies may be slow coming until almost midnight

Blue91Z28

I understand play-offs. I am watching football Monday night. War Eagle!

Blue91Z28

Moving to the garage for a while. Wish me luck.

Scorpner

iTrader: (4)

I'm sorry, but it's -7° out today so that's out of the question. There are a few tips if you read through the pdf and I was thinking that by seeing how it goes together you could get a decent idea of how it works. It will also help when talking about parts and identifying which version you have.

Many times a visual check will reveal a broken gear nut or housing mount/s which are very common. If not, then check the relays. I would try to check the relays in place in case there are issues with the wiring. Many times it becomes difficult to recreate an issue after a unit is removed and wiring moved around because an open sometimes reconnects leading to a false test where everything appears fine. If the switch is defective then a meter check will reveal that as well vs. listening to it clicking.
On the other hand, a relay can also cause the mentioned parts to fail as well. An example may be a relay failing which causes the motor to overrun and break the gear nut. The gear nut is designed to break so that the motor won't stall and burn out. Motors seldom fail from what I've seen.

enswrob

lon over at top-down solutions has the parts to rebuild the hatch nut, guides, case reinforcement.

Blue91Z28

I know he does have all the parts. I got the new motor and reinforced gear housing from him a while back. Great products and great service!!! The problem I have is I don't know if I need to replace parts or which ones I need if I do.
I think my reverser switch may be bad but I don't know how to test it.

mjones89

Please Help Having Same problems with Hatch Motor. Bought the new one From top down solutions and read and followed all assembly instructions completely. Hatch motor will rotate upward one turn then stop. I have disassembled and reassembled the entire unit so many times and can not figure why its not working properly. Could it be the Relay or The Reverse switch.... PLEASE HELP!!!!

NINÅ

xx138xx

You said you dont hear a click when you push the hatch release. If I recall correctly there is relay in the dash on the passenger side. Its for the hatch release button. It should click pretty loud if the relay is good.I would check that relay.

Blue91Z28

The latch broke again. One Very Pretty 1991 Z28 350 tpi POS for sale. PS the hatch will not close properly. Everything else is in very good condition.

Ron U.S.M.C.

Over 8 years ago, before I was a member here, I took a non working hatch pull down motor and made it stationary. I close my hatch the same as a standard trunk. Even with nice and strong hatch shocks it closes surprisingly easy/nice and soft with the new weather striping.
It was supposed to be a temp fix.

Keith Maloy

Thanks for the info. on the parts for the back hatch this is exactly what I needed to find!

Nelz

Where does this white wire from the relay go? The wiring diagram says there is one white wire that goes to the cargo light and one that goes to the pull down motor. But there is already a white wire to the cargo light. I'm trying to fix my hatch pulldown and I seem to have one broken ground that I can't figure out, and one white wire that seems to be broken. Before I fix the connector and stick them together, I just wanted someone to check that they even go together. Using a test light on the striker switch and pulldown motor connector, I have power to all the wires EXCEPT the white one. I trace that white wire and there is a junction where another white wire comes out that I have no idea goes where. And I have a broken ground wire. Can anyone tell me if they go together?

padak

iTrader: (10)

I am over my hatch motor.. how do I do this?

Edit: 1987 Trans Am

Nelz

Here is how I think the motor works (please correct me if I'm wrong.)

If you hit the hatch switch in your console, it sends a signal to the lock to unlock and a signal to the hatch motor to raise. The raising of the motor and the hatch struts are enough to open the hatch.

When you place the hatch down and it hits the striker switch, the striker switch (the little black switch where the hooks hook onto the hatch) sends a signal to the motor to reverse and pull down the hatch.

GM's factory manual says to change the entire assembly because only three to four things can go wrong electronically:
1. The Striker switch is not sending a signal to revers the motor
2. Reversing switch
3. The motor is not working.
4. The relay is not working.
5. Something is jamming the motor from pulling the hatch down and that's why you read that if you can hear the motor working, the gears are turning but something is jammed or broken like the nut that the motor is turning has broke, or those channels have broke.

As to reading the diagram and testing for what to isolate is broken (relay, striker switch, motor) I haven't figured it out yet.

If you hit the hatch open switch from the console and hear a noise, then it's not the lock mechanism because it's still unlocking.

If the motor is not going up or down, it can be any of those three things mentioned above. The striker switch, the motor or the relay.

I stuck a test light to all the leads from the Relay and the purple one has power (which means that it's not the fuse in the fusebox because I'm still getting power.) I stick it in the orange wire and I have power, I just have no power on the white or black. (I'm assuming the black one is ground, but is the white wire supposed to have power? I need help here.)

I stick a test light into all the contacts on the reversing switch where the wires go and blue, orange have power, but not white or black. I stick the test light where the motor meets the plastic housing and my test light goes on. I stick the test light to the striker switch and I have power on the orange and brown but not the white wire.

What part is broken to cause the motor to not pull down? I press the striker switch and that would normally reverse the motor and nothing is happening so I'm suspecting the striker switch is gone but I'm wondering if anyone else has any experience or theories? (I replaced the relay and the motor a few years ago and the striker switch was the only thing that I didn't replace but my whole assembly worked this summer until one day it didn't.)

Joe Tag

iTrader: (4)

Your loose ground wire.... where does the other end go to? You have two black wires on the pulldown motor harness. One goes to ground and the other goes to the latch switch. Both are connected to the same pin "B" on the relay. The white wire is unused in your setup, you have a manual switch for the cargo light.

Nelz

I fixed the ground. It goes to the trunk lock solenoid. But still not pulling down. I do remember hearing the relay click but I can't remember if I pressed the striker switch to do that or if it just happens when I probe the relay with the test light on one of the wires. Will report back