The trunk release is a simple powered switch in the glove box.
Key on test, after checking the A/C fuse which powers it, orange wire at the switch should have +12 on it to a good ground using a test light or meter.
Out of the switch when pushed should also be +12 on the black wire.
It usually breaks at the bend point right at the drivers side trunk hinge.
Thick plastic coated wire.
If you have power at the switch and out of it, check that area of the trunk, usually a visual or a feel of the plastic cover will tell you where the break is.
Black wire at the trunk release solenoid is the +12 feed, the body is grounded to the trunk via the mounting bolts.