Ac compressor when i push the botton to turn a/c on i will not cut on and when i jump that pressure switch cluch does not engage, however if i jump that a/c clutch relay switch that ac turns on and off when i push da button. what do i need to ck bc pressure switch and relay was changed and fuses are good

there are two pressure switches in an ac system
one switch prevents the compressor from running if there is too much gas
the second is to prevent the compressor from running if there is insufficient gas
from what you describe , one of those switches ( most likely no gas) is the switch
check for oil dust around the fittings , condenser or have an ac specialist check for leaks and regas

It is doubtful the fuse is an issue, check the refrigerant charge in the AC system, if it is low the compressor will not engage. You can jump the low pressure switch to turn on the compressor, that will verify the electrics are all ok. The switch is located in the low pressure AC line from the compressor on the engine, it is the larger of the 2 lines coming from the AC compressor.

most likely the ac compressor will not engage because it needs a freon charge.The simple way to tell if that is why without having special equipment is to find the pressure switch located on the low pressure line and jump the switch with a peice of wire. if the clutch engages when you jump the switch then you need to charge the ac with 134 a freon

If the system is low on charge then the compressor will not engage. The first thing you need done is to have the pressures checked in the system, if they are low find the leak and repair it before recharging the system.

Most vehicles have a low pressure switch that prevents the compressor from engaging so as to prevent damage to the compressor. You need to place a gauge set onto your AC to read the high and low sides of the system. Probably have lost enough gas(R134) over time to prevent the compressor from engaging. You can jump the pressure switch to check it with a simple jumper wire.

There are a few reasons for the compressor not engaging. Lets start with the most common. low ac gas.A bad clutch on the compressor.Blown fuse.
Let is start with testing for low gas. (134a freon).Locate the dryer. this is on the passenger side of engine compartment. it looks like a tall cylinder, on the top side you will see a switch. unplug switch connector and jump the two terminals in connector with a piece of wire, this is the low pressure or cycling switch. you will be completing the circuit by jumping a wire across the terminals.If the compressor turns on when connectors are jumped then you are low on gas and the system needs recharging.
If the compressor does not urn on then check all fuses, if fuses are good then the next step is to go to compressor and test for power and ground. If you have power and a good ground on the connector to compressor then compressor clutch is bad.A bad clutch will some times blown fuses, so if you replace the fuse because it was blown and it blows again then clutch is bad.
Another test that will help is when you remove the connector from the cycling low pressure switch , test the connector. one wire on the connector should have power when ac is turned on,
Hope this helps let me know what the outcome is. Good day.
I have enclosed a picture of the switch and dryer to help you locate it.If you jump the terminals

This could be a few things. The freon could be low, one of the switches (high or low pressure) could be bad, or you could have a bad compressor clutch. You can test the clutch by checking for battery voltage and ground at the two pin connector with the A/C on if you have both power and ground, then the clutch is bad. You really should start by hooking up pressure gauges to the A/C ports to check the pressures, and these vary depending on ambient temperature and whether the A/C compressor is engaged or not. I am willing to bet that the freon is low though and may be just as simple as recharging the system.
Hope this helps. Good luck!

the control unit is no good.i had a similar situation with a 98 tracker,and installed a switch to give it a ground for the compressor relay that comes from the a/c computer module.
it works good and goes on and off with the a/c switch.

Did you put freon in the car? If you did, and you have too much, there is a "high-pressure" cut off switch, and there is also a "low-pressure" cut off switch. So, if the freon is too little or too much, the AC is prevented from engaging. The best thing to do is take it to a guy who has freon pressure gauges; this is the only way to tell if the charge is correct or not.

The pressures of the refrigerant must be close or the system pressure sensors will not let the AC cluch pull in. AC is just not wise for DIY without some gauges and knowledge. Sorry.