Ikes 91Z

iTrader: (1)

So my trunk is not pulling down when I close the hatch. I have put a new motor on, as well as new guides. The hatch is still not being pulled down once it is latched. When I hit the latch release, the latch lets go so I know there is power going back to the motor. Does anyone have any other suggestions on what I need to look at??

John in RI

iTrader: (167)

The hatch release is not "connected' to the PPD motor in that way. Consider them to be seperate systems to help solve your problem. The hatch release is always grounded and gets power from the relay when the button is pushed. The PPD motor should be getting power at all times thru the body harness and the ground wire is screwed to the body near the hatch motor.

Probe the red wire on the body harness (or dark blue wire depending on year) at the hatch motor to see if it's getting power. If you simply installed a used hatch motor without seeing it work in advance then there's a real chance it could also be a dead unit.

Did you check the PPD hatch motor fuse in the fusebox yet ??

NCC-2569

iTrader: (1)

Here's a little something.
When you're done with John in RI's suggestions and power is indeed reaching the motor, post a pic of the motor model you have.
If you've got something like this (borrowed the image from TDS):


There are two things you can check.

1: on the bottom left of the pic you can see the motor housing. Perhaps the brushes are done or simply misaligned somehow. Was the case in mine. It's tricky to get it back together, though, so you'll need patience.

2: In the middle where all the cables go, there is a black box, the reversing switch (borrowed from Hawk's).

This bugger tends to be my #1 case of malfunction. I removed it, cracked the studs with a drill and loosened the tiny screw. I'm using a zip tie to keep it together afterwards.
Inside is a little sled with copper contacts on the bottom and this part likes to get stuck somehow and the motor will never ever engage as long as this part does not move.
Clean it up, possibly use some sanding paper to roughen up the contacts on the sled and apply a tiny amount of WD-40 or similar stuff to the sled tracks.
Reassemble and test the unit after plugging in all the cables. You can test it by pushing down the plastic part of the locking mechanism.
The box HAS to CLICK audibly at the end of the movement or it's stuck again.

I need to document this properly next time, because I had this issue on both my F-bodies and it's actually a quite easy fix and the only way IMO to keep that thing running for a longer time.

Ikes 91Z

iTrader: (1)

The motor itself is a brand new motor (I didnt buy a used one for the exact reason you specified). So it has to do something with not getting power.

I will check the fuse, and check the voltage on the wire to make sure. If it isn't those I will have to dig into the reversing switch and see if it is the copper contacts.

I will let you guys know what I find once I am done.

Ikes 91Z

iTrader: (1)

So I finally had some time to dig into the problem...

Fuse was good, and had power to the motor itself. So I took apart the reversing switch and found some corrosion on the bottom of the moving piece that gets stuck. So I cleaned that and put it back together, and somehow it's working!

Not sure how long it will keep working with the corrosion bound to come back, but at least I know what will need to be fixed the next time.

Thanks for the help gentlemen!

lonsal

iTrader: (2)

I use some contact cleaner on the contacts inside the reversing switch when I refurbish them. I also use synthetic grease, but a little white lithium would also work.

That 2nd photo that was grabbed from Hawks website is of one of my refurbished reversing switches.

Everyone rebuilding one of these 1986-91 pull-down units should check out the Tech Article I wrote that is posted here on TGO under "General Repair" category.

Lon