Convertible top The motor on my '98 Z3 will no longer raise the convertible top. How difficult is the fix? Is there any way to disconnect the motor and close it manually?

There are only Two things in the right rear the pump motor and the top ajar switch. This sounds like the motor is locked up or the top is jammed or going the wrong way. First disconnect the motor and if the noise stops it's the hydraulic unit trying to move the top watch the top to make sure it's going the right way, the top ajar switch could be bad. If you're confident in the hydraulic unit and motor the only thing left is a jammed top, a bad connection at the hydraulic unit, or the top ajar switch. I hope this helps. Take care.

Principles of Operation
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 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.

Inspection and Verification

1. Verify the customer concern by operating the system.

1. Visually inspect for obvious signs of mechanical or electrical damage.
   
   Visual Inspection Chart Mechanical Electrical
   • Door and quarter window glass adjustment.
   • Convertible top brackets and frame.
   • Hydraulic motor and pump.
   • Hydraulic lift cylinders.
   • Central junction box (CJB) Fuse 20 (15A).
   • Battery junction box (BJB) circuit breaker CONV TOP (25A).
   • Wiring harness.
   • Loose or corroded connections.
   • Raise or lower relays.
   • Parking brake switch.
   • Convertible top switch.

1. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

1. If the concern is not visually evident, verify the symptom and refer to the Symptom Chart.

Principles of Operation
Convertible top operation is controlled by the smart junction box (SJB). When the convertible top raise/lower switch is operated, the SJB commands the front and rear windows to the full down position. Window operation is disabled while the convertible top raise/lower switch is being operated. When the SJB receives a full down input for both rear windows, it commands the appropriate relay closed to raise or lower the convertible top. If the SJB does not receive a full down input signal for both rear windows, the convertible top operation is disabled.

The convertible top hydraulic system uses a 12 volt reversible pump and motor assembly. When active, the pump uses hydraulic pressure to extend the hydraulic lift cylinders to raise the convertible top, or retract the hydraulic lift cylinders to lower the convertible top. The convertible top motor/pump assembly is equipped with a thermal circuit breaker. The circuit breaker typically resets after 5 minutes depending on the ambient temperature. The thermal circuit breaker cannot be repaired and must be installed as a unit with the motor/pump assembly. In the event of a hydraulic system failure, the convertible top cannot be operated manually.

Inspection and Verification

1. Verify the customer concern.

1. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart Mechanical Electrical

• Convertible top brackets and frame
• Convertible top latches
• Convertible top pump and motor assembly
• Hydraulic lift cylinders
• Hydraulic lines

• Bussed electrical center (BEC) fuse(s):
  • 13 (40A)
  • 51 (10A)
• Circuitry
• Convertible top pump and motor assembly
• Convertible top ajar switch
• Convertible top switch
• Connector(s)
• Convertible top raise relay
• Convertible top lower relay
• LH or RH rear power window motor
• Smart junction box (SJB)
• BEC

1. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

1. If the cause is not visually evident, connect the scan tool to the data link connector (DLC) and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle:
   • check that the program card is correctly installed.
   • check the connections to the vehicle.
   • check the ignition switch position.

1. If the scan tool still does not communicate with the vehicle, refer to the scan tool operating manual.

1. Carry out the scan tool data link test. If the scan tool responds with:
   • CAN or ISO circuit fault; all electronic control units no response/not equipped, refer to Section 418-00 .
   • No response/not equipped for SJB; refer to Section 419-10 .
   • System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs, and carry out self-test diagnostics for the SJB.

1. If the DTCs retrieved are related to the concern, go to the Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index.

1. If no DTCs related to the concern are retrieved, GO to Symptom Chart .
2. Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index DTC Description Source Action B1141 Convertible Top Full Down Position Switch Circuit Failure SJB Go To Pinpoint Test E . B1142 Convertible Top Full Up Position Switch Circuit Failure SJB Go To Pinpoint Test E . B1402 Driver Power Window Down Switch Circuit Failure SJB Go To Pinpoint Test A . B2068 Convertible Top Up Output Circuit Failure SJB Go To Pinpoint Test A . B2069 Convertible Top Down Output Circuit Failure SJB Go To Pinpoint Test A . B2481 Convertible Top Up/Down Switch Fault SJB Go To Pinpoint Test A . B2578 Passenger Power Window Down Switch Circuit Failure SJB Go To Pinpoint Test A . All Other DTCs - SJB Refer to Section 419-10 .
3. Your best bet ,take it to a qualified repair shop !

It is a hydraulic pump that applies pressure to the 2 hydraulic pistons to raise & lower the top. So, check for something obstructing movement first.

The convertible top:

• is motor-driven.
• requires parking brake engaged to complete circuit for operation.
• is equipped with a back window glass (42006) . The back window glass is permanently attached to the folding top back window curtain (52500) and cannot be opened.

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VISUAL INSPECTION CHART Mechanical Electrical

• Damaged fluid reservoir.
• Damaged folding top hydraulic cylinders .
• Damaged folding top motor upper and lower hose .
• Damaged convertible top regulator.
• Parking brake not engaged.

• Open power distribution box circuit breaker CONV TOP (30A), fuse junction panel Fuse 1 (15A).
• Circuitry open/shorted.
• Damaged convertible top switch.
• Damaged raise/lower relay .
• Damaged folding top hydraulic lift motor and plate kit .

• Convertible Top Does Not Raise/Lower

• Open circuit breaker or fuse.
• Circuitry open/shorted.
• Damaged folding top switch.
• Damaged raise/lower relay .
• Damaged folding top hydraulic lift motor and plate kit .
• Parking brake not engaged.

your need to have the motor and that circuit check and the modules on the vehicle the operate those functions

Before you even begin, I would check prices and availability. A lot of top parts for this are no longer available or VERY expensive. All parts are under panels in rear. Just be patient and remember where they go.

Cadillac never built a 1985 Eldo convertible. It was custom made. A schematic will be difficult to find. Hope this helps

Check all your fuses there must have been a cut fuse that is not enabling power to reach it.

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You must ensure that you have your foot on the brake and both windows are half down