What would cause an AC clutch to not engage? Many reasons. A bad clutch,pressure sensor, low freon, no ground, no signal, bad module, bad controller, wires shorted, burnt fuse, burnt relay.

By using a clutch mechanism, engineers designed A/C systems that don't have to be on all the time. Using a clutch mechanism to connect the compressor to the engine not only increases fuel economy, it also increases the useful life of the vehicle by reducing stress on its engine.

Take the fused jumper wire and connect its one end to that side of the wire connector that was connected to the compressor. Attach the other end of the jumper wire to the positive terminal of the battery. It will supply the battery voltage to the compressor clutch, allowing it to engage manually.

Consider the following possibilities: Low Refrigerant Levels: Insufficient refrigerant can prevent the clutch from engaging. Have the refrigerant levels checked and recharged if necessary. Compressor Issues: A faulty compressor, such as a seized or damaged compressor, can affect the clutch's operation.