1999 Nissan Sentra AC pump

Hi pringle and TY for the donation

If the compressor does not engage when you turn on the A/C, see if it will run by jumping the compressor clutch wire directly to the battery (use a fused jumper wire). If the compressor works when you jump it, and the A/C blows cold air, the system contains refrigerant and the fault is likely a bad A/C compressor clutch relay or a bad clutch cycling switch or pressure switch.

If the compressor does not engage when you jump it, the problem is a bad compressor clutch.

If the clutch engages but the compressor does not turn (the belt will start to slip and squeal), the compressor is loced up and you need a new compressor.

If the compressor clutch engages and turns the compressor, but the A/C still does not blow cold air, the system is probably low on refrigerant and needs to be recharged. If you Have an A/C gauge set, hook it up and see if the system has any pressure.

If it is out of refrigerant or is low, check for leaks, then have the A/C system vacuum purged to remove air. After the air is out, it can be recharged with the specified amount of refrigerant. It is important to get any air out as this will reduce cooling efficiency and may make the compressor noisy.

My advice to you if you know nothing about A/C service is to find a repair shop that specializes in A/C repairs and let them fix your cooling problem for you. Today's A/C systems with automatic climate control are very complex and reuire special tools and know-how to diagnose and repair.

I've sent it to your hotmail let me know how it comes out