Crossfire1952, welcome to the forum!

You always have to open the pressure relief valve on the pump in order to manually lower it. This is not an indication that the pump builds enough pressure; you are merely bypassing a check valve that gets engaged any time fluid moves back into the pump from the bottom hoses of the main lift hydraulic cylinders.

The Hall effect sensors rarely ever fail, and they would be the last thing I would check on the whole electrical system for the top.

Here are some questions that we need answers for:

Have you checked all applicable fuses and made sure they have good contact?
Do you hear the pump running at all?
Will the pump run if you short out pins 30 and 87 on either of its relay sockets (one at a time), which would supply 12VDC directly to the motor?
Have you made sure that you get signals for "trunk lid closed" and "divider closed" all the way at the connector to the controller?

One more detail before we get into the Hall sensors and after the above questions have been covered, is whether the soft top controller actually gets the signal that the windows are down - I don't recall from memory how this is done in the Crossfire, but you can find out from the service manual. Please let us know for future reference.

For completeness, below are some more details about the Hall effect travel sensors on the Crossfire convertible top hydraulic sensors.

The aluminum cylinders on the left side have travel sensors on them, which are Hall effect sensors. They can be found on the tonneau cover cylinder p/n 05142641AA, on the left bow tension (folding top rear bow) cylinder p/n 05142640AA, and on the left main lift (main drive) cylinder p/n 05142639AA.

Hall sensors pick up the change of the magnetic field near them. They have a magnet built in, and the magnetic field changes depending on how much ferromagnetic material is nearby. The cylinder's shaft and piston are made of ferromagnetic material, and the piston being near the sensor or not makes enough difference for the controller to figure out the cylinder's status with respect to being extended or retracted. There are many ways that the Hall Effect can be used in sensors, depending on how you configure them. In this case, the controller measures the current passing through the Hall sensors when a modulated 100Hz signal is applied. That current varies depending on the magnetic field change and the position of the cylinder shaft in the cylinder. The actual change in current is a few mA.

We could go into this a little further, but it is likely going to be too much of a distraction for future readers, simply because the Hall sensors rarely ever fail. What could fail, are the wires going to the sensors. A simple enough test would be putting a multimeter on the sensor pins of the connector to the controller, once unplugged. You have the pin-out in the diagram that ala_xfire has provided. In one direction, you should measure practically open circuit, and in the other direction you should get a number of MOhm. If you get that, then the wires are okay, and the sensors are almost certainly working.

Klaus
Top Hydraulics, Inc



Location of the hydraulic components in your Crossfire roadster convertible top system