1956 power trunk lock

[Steele24X]

Hey everyone! My power trunk lock is either dead or needs to be rebuilt. Not 100% sure on it yet but was hoping someone could fill me in on them and how to get them up and running. The lock that you put the key into on the trunk lid to unlock it is also stuck but when I push the release button in the glove box the latch releases. Thanks!

[Cadman-iac]

 The release solenoid operates separately from the pull down unit.
Does the pull-down unit raise at all once you release the lid? If not, it could be something as simple as a broken wire, or a bad ground connection.
However,  the switch that controls the unit can also be suspect. Can you take a few pictures of it from various angles and post them here?

  Rick

[Steele24X]

I will take a couple pics. How do you test the motor for activation of up and down? The pull-down unit does nothing right now so the trunk lid is just free floating.

[Lexi]

The power trunk assist unit was offered late in the 1955 model year. Here are scans of an original GM General Service Letter plus a wiring diagram from my collection that should assist as the 1955 and 1956 units were identical. Also posted is a copy from the 1959 MPL that further detail these units. At some point you may have to get in the trunk and have a friend open and close the lid with you inside, to test and visually inspect. Ensure that you are in there on a cool day, with tools (and lights) necessary to get out in the event of a mechanism failure. This would be especially true if your car has AC as there is no access to the cabin through the rear seat due to the evaporator unit. Being somewhat claustrophobic myself, I spent a "week in there one day", and was glad to get out! Clay/Lexi

[J. Gomez]

  Clay beat me to the punch..!

Sam,

I can tell you that 90% of the time the issue with the trunk pull-down the main problem is the striker switch. Most of the time the switch overheated and melted the plastic enclosure or the wires are broken at the main base of the enclosure.    The ones I work on were almost getting ready to fail but was able to salvage the plastic cover and refurbished them.   

Just as a FYI the push button on the glove compartment is for the main solenoid on the lock, this will pull the lock to open the trunk.

Both the motor (via the striker switch) and the solenoid get power from the same CB but they are feed independent, since the solenoid works have you check power at the “Black” wire which goes to the switch, you should have +12V there?

The striker switch feed the +12V to the motor depending on the position, switch “up” the motor will lift the striker and the limit switch will stop it and will switch the power to the close position. When the trunk is close (switch “down”) the motor pull the trunk down to close it until the limit switch stops the motor and reverses the power for the next cycle.

HTH

Good luck…!