1960 Power Trunk problem

[60eldo]

  So if the car has PT but its not working and stuck in the closed posiion, should the trunk still close and open using the key?

[76eldo]

Depends.  Should unlock with the key unless the mechanism is rusty and binding.  Should close since the pulldown motor is probably retracted.

Brian

[SixDucks]

Brian is correct, the key should open the trunk. I would certainly spray some lube into the lock. I believe that release button located in the glove box is actually vacuum operated. You may want to check for rubber hoses in the back of the button. If in fact yours is vacuum actuated you may start looking for a broken hose. If the engine does not operate use a hand operated vacuum pump and attach to the port, give a few pumps and depress the button.
Hope this helps.

  Terry

[60eldo]

  Whats happenning is when I go to close the lid its not catching. Ive tryed to adjust it but no luck.

[SixDucks]

Clean and lube the mechanism. You may find that the cable is frozen or has become disconnected to the hydraulic cylinder located at the trunk hinge.

Terry

[76eldo]

There is no hydraulic cylinder that I am aware of.  The Pulldown is complicated but if it's down it should latch.
\
Brian

[60eldo]

    Brian I agree, theres no power there, the latch is down, but the lid wont catch

[The Tassie Devil(le)]

Could it be that you have to really bang the lid down hard?

If it was correctly latched some time ago, and the motor pulled ity down tight, then once you have released the pressure, the gasket sprang back into shape, and now required really compressing hard to allow the catch to latch.

I aligned the doors on one of my vehicles, then installed the new rubbers, and I had to really SLAM the doors to get them to close in their correct alignment.   In this case, the gaskets had a couple of filled spots, where it was supposed to be hollow, but I too was at my wits end.

Bruce.

[quadfins]

First, 1960 trunk systems are electric, not vacuum or hydraulic, so those can be eliminated.

Second, it sounds like one of the microswitches in the mechanism is misadjusted or inoperative.

The way these systems work:

Starting with the trunk open:

The electric motor has moved the latching assembly upward, and at a determined height, a microswitch has cut power off. another microswitch has sent power to the TRUNK warning light in the dash.

As the trunk lid is slowly and gently closed (NEVER slammed), the latch (in the trunk lid) engages the pull-down bar on the mechanism, and also engages a microswitch that sends power to the motor, which now engages a jackscrew that pulls the mechanism (and with it the trunk lid) further down until it seats on the rubber seal and "locks" the lid. As the lid stays tightly in place, the motor continues to pull down, now also against the resistance of the lid, but also against a tension spring in the mechanism, near the jackscrew.

Another microswitch is adjusted to cut off power when the pulldown mechanism reaches a predetermined pressure of tightness. The trunk lid is now closed and locked, and no power goes to the motor.

If the key is used to unlock the trunk, the physical movement of the key releases the latch. As the latch releases the trunk lid, the lid moves up slightly (opens), due to the pressure of the rubber seal pushing back at it, and the trunk springs, which naturally want to open the trunk lid. The upward movement of the latch relieves pressure on the microswitch, which now directs power to the motor, turning the jackscrew, and raising the pull-down mechanism. At a pre-determined height, the original microswitch is activated, cutting power to the motor, which now stops, and the system is reset, waiting for the trunk lid to be lowered, activating the system as from the beginning. It also activates the trunk warning light in the dash.

If the release button in the glove box is used, it sends power to a relay in the trunk, which then forwards power to the magnetic release mechanism in the trunk lid latch, which releases the latch from the lock, rather than the key.

So, What is to be Done???


First, check that power is available to the motor.

Next, check that the motor actually operates. In your case, it sounds like the "return" switch might be misadjusted or inoperative. Push down on the flap (the one my finger is on in the pictures) and see if that activates the motor.

If both are OK, then the problem is most likely in the microswitches, either in that they are misadjusted, or broken or inoperative. The unit will need to be removed, investigated, and possibly repaired.

Easy check one... Open the trunk, and gently push down on the thin metal "flap" under the bar where the trunk latch would hook onto. If you push on the flap, it should activate the motor and pull the unit down. Keep holding the flap down until it clicks the other microswitch, and reverses the motor, moving it back upward.

If you can do this manually, and the motor moves, it is probably a simple adjustment of the sensitivity of the switches. If not, lets investigate other symptoms and track down the problem.

Hope this makes sense. If I can find some pics, I will post them in a follow-up.

Jim

[quadfins]

switch and mechanism pics

[60eldo]

  Heres what I have, theres no power to the car right now, I just want to know if the lid should shut, its not.

[quadfins]

Looks to me as though the mechanism is at the low end, so it is unlikely that the trunk latch on the lid would be able to connect and engage, thus holding it down.

Do NOT slam it down, in the vain hope that it will engage. That will most likely only damage the lid and other components.

If you absolutely just have the trunk lid latched closed, perhaps you can run a power source to the motor, and follow the steps outlined above.

Jim

[SixDucks]

Jim,
Thanks for clearing my misinformation up. I did a quick search on this matter late Saturday night ( too late to post my findings) and found a thread from June of 2017 detailing the years an electric motor was used versus the mechanical latch. It baffles me that Cadillac discontinued use of the electric pull down in favor of the mechanical pull down that my '62  and '63 Fleetwoods utilized. As for the hydraulic cylinder I mentioned, I meant the shock absorber. (Isn't that a hydraulic cylinder of sorts?) Either way thank you. I learned something new.

Terry

[quadfins]

It was enjoyable to write out the description. Maybe with some more details and editing, it could become a tech article.

More than anything, when I find out how these systems work, it gives me a greater appreciation for the engineering and creativity of the time.

Jim