Carlisle Hydrastar Electric Over Hydraulic Trailer Brake Actuator Does Not Cycle On/Build Pressure

Updated 06/07/2012 | Published 06/05/2012

Question:

Im trying to trouble shoot above referenced Hydrastar. 3-4 year old unit has workied properly in past but no longer can hear motor running when unit has confirmed 12volts to unit. I hear a click only and the brake lines do not pressurize. Any ideas?

asked by: Bill K

Expert Reply:

Your Hydrastar actuator is not cycling on to build pressure to apply the brakes when needed. This could mean that there is an electrical problem or a malfunction with the motor, or even a problem with the brake controller You have stated that there is confirmed 12 volt power going to the unit but it could still be an electrical problem.

You can also make sure that the Hydrastar white ground wire is connected to the vehicle ground and not to the trailer. They are very particular about this ground connection and it must be connected to the vehicle ground.

To further test the unit, leave on the blue, black, white, and yellow (or blue with white stripe) wires. Make sure it is disconnected from any other wires going to the tow vehicle or breakaway system.

Use a separate 12 volt battery and connect the white wire directly to the negative terminal then connect the black wire to the positive terminal. The motor should NOT run at this time. If it does then there is a problem inside and it will need to be repaired by Carlisle.

Next leave the white wire connected to the negative terminal then connect the blue and black wires together to the positive terminal. The motor should now run and pressurize. If it does not, it will need to be repaired by Carlisle.

Then you can leave the white wire attached and connect only the yellow or blue wire with white stripe to the positive terminal. the motor should run and pressurize. If not, it needs to be repaired by Carlisle. If everything checks out then reconnect the unit to the trailer connector and repeat the tests again. If it does not work then there is a trailer wiring problem or problem with the brake controller.

If you recently changed brake controllers or vehicles and the new vehicle has an integrated controller, that could be the problem. There are only certain brake controllers approved for use with the Hydrastar.

expert reply by: Michael H