Convertible Top Electronics/Hydraulics


Wiring Diagram

The convertible top will only operate with the parking brake engaged and the ignition switch in the RUN position. When the parking brake is engaged, the raise and lower relay coils are grounded through the parking brake switch. The Generic Electronic Module (GEM) also lights up the "brake" indicator on the dash.

The convertible top switch supplies power to the raise or lower relay coil when raise or lower is selected. This power energizes the coil causing the relay contacts to close which supplies battery power to the convertible top motor/pump assembly.

The normal state of the relay is connected to ground. When the raise or lower relay is operating, the other relay remains in its normal state supplying the motor/pump ground.


The Hydraulic System

The convertible top hydraulic system is comprised of a hydraulic pump, two lift cylinders, and the connecting hydraulic lines. The hydraulic system is removed as an assembly, but the components may be repaired separately.

Servicing the Hydraulic System

  1. CHECK THE FLUID LEVEL
    • Place an absorbent cloth below the filler plug when checking the fluid level.
    • Remove the filler plug and check the fluid level.
    • The fluid level should be even with the bottom of the filler plug hole.
  2. CHECK THE HYDRAULIC SYSTEM FOR LEAKS
    • Inspect all fittings and hoses for leaks.
    • REPAIR any leaking fittings or INSTALL new hoses as necessary.
  3. BLEED THE SYSTEM
    • Remove the hydraulic system from the vehicle.
    • Remove the fill plug at the end of the hydraulic pump.
    • Fill the pump with MerconŽ Multi-Purpose Automatic Transmission Fluid XT-2-QDX or equivalent to the bottom of the fill hole and install the fill plug. (Some noise squeal may be noticed due to the air in the system.)
    • Connect a 12-volt power source to the motor connector and operate the motor until the cylinders are fully extended. Reverse the 12-volt connection to fully retract the cylinders. Repeat this procedure three times.
    • Remove the fill plug and check the fluid level. Fill the pump with MERCONŽ Multi-Purpose Automatic Transmission Fluid XT-2-QDX or equivalent to the bottom of the fill hole.
    • Install a fill plug.
    • Install the hydraulic system in the vehicle.

Troubleshooting

If the convertible top does not raise/lower, does not go up all the way, or hesitates/comes up uneven, check:

  • Convertible top switch.
  • Fuse 20 (under dash)
  • Parking brake switch.
  • Raise/Lower relay U (under hood)
  • Convertible top adjustment.
  • Hydraulic lift cylinders.
  • Hydraulic motor/pump assembly

Useful references:
Ford Convertible Top Repair and Adjustment Manual
How to Install a Convertible Top

Source of Replacement Convertible Tops:
LateModelRestoration.com