It worked yesterday, and today, my hatch motor is stuck in the UP position. I can pop the hatch open and closed... but the motor wont engage making the hatch pull down the rest of the way. I'd do a search for this, but the search is shut down. I checked fuses, my chilton, and my haynes. Fuses are good, and the books have nothing on the hatch motor. Help?

 

The hatch pull-down is powered by a completely different circuit than the hatch release. First check the fuse (15A third from the left in the top row). Even if it looks good replace it. As is often suggested, it you fiddle with the switch near the latch and get it to work, that means that switch (called the striker sensing switch) is going bad. I've seen several fail to actuate the unit when the hatch hook is tripping it. The contacts in them just wear out from use. If playing with the switch does nothing (this still doesn't mean it isn't bad), then unscrew and remove the back panel covering the pull-down unit. Disconnect the blue wire from the red with white stripe wire. Test that you have +12v at the red/wht wire. This wire is hot at all times and is the only power to the unit. My guess is either the motor or the striker sensing switch are bad. You'll need to disassemble further to get to the contacts where the reversing switch mounts to test the motor. All items to repair these units are available through my web site. Here is the tech article I wrote on disassembling and repairing the unit. The tech article covers both the 1986-87 & 1988-91 units (despite what the title indicates). Follow the steps in the tech article and you'll be able to repair the unit yourself.

Good luck,

Lon Salgren
Top-Down Solutions

 

I did play with the switch and nothing happened. Thanks for the website/article I'll tackle it tomorrow morning.

PS, what is the sqaure box looking thing... looks kind of like a relay... has 2 white wires/ 2 black wires/ 2 blue wires/ and a brown wire going to it.

Thanks!

 

Relay. I stock it also.

Lon

 

I looked over your PDF and it just shows me how to repair the mechanical part of it. I'm not getting anything from my motor which leads me to believe it is something electrical. Do you have a source for testing the electrical aspects?

 

In that picture, bottom left... there is a white wire with a black connector end on it. I have that on my car, and it doesn't seem to be connected to anything....?

 

I could send you the scans from the HELMS manual. But it wouldn't tell you much more than I've already described. The manual recommends replacing the entire unit if it fails to work. Get out 4 bills if you folow their advice.

You'll have to disassemble the unit using my instructions to get to the terminals on the motor to test it. DO NOT remove the metal cover on the motor. More than likely you'll just break the brushes trying to disassemble or reassemble it. Use long jumper wires with alligator clips on the end hooked to your battery to provide +/-12v power to the terminals that the reversing switch attaches to. Test it both forward, then reverse the wires and run it backward. If it is weak or noisy, the brushes are badly worn. I haven't found a source of new brushes. If the motor is bad you have two choices. Replace it with a new-style motor (which includes a new plastic motor housing, that the gear nut drops into) or a replace it with a good used one. That old-style motor was discontinued by GM.

That white wire connects to the orange with black stripe wire to turn off and on the hatch light on 90 and up cars. On yours it connects to nothing. I'm assuming you have the manual switch to turn off and on that light.

Lon

 

I tested the motor, and it works. Relay I can hear click on and off by running power to it. By crossing white and orage wires at the motor switch (not the striker switch) nothing happens. On my friend's of the same make/model/year it moves the motor. So My guess is, is that it's that 4 wire mechanism that connects directly to the motor. :O)

Thanks for the help. I'll be ordering the part from your site soon if you concur with my findings.

 

That would be the striker sensing switch. If it were me, I'd still disassemble and test the motor terminals directly before ordering. It only takes a few minutes. The striker sensing switch contains all the wiring to the unit. Just swap your relay onto it. Whichever you find is the probem, I have the part in-stock.

Lon

 

I tested the motor terminals bare... and the motor works. So it's the striker switch or the reversing switch....