1997 Jeep Wrangler A/C Issues

[Walkerman]

After driving a few miles (it varies) ac comp. kicks out.
Changed low pressure switch. No Change..
TODAY: Drove it for 15 minutes and quit cooling.
After it quit I checked to see if the clutch was engaged. It was not.
I then disconnected the wire connecting to the LP switch and jumped it
with a wire. The clutch engaged and I kept the jump for 45 seconds.
Worked OK as long as I held the jump.
What is this telling me ???

 

[Rickyd]

Low charge and a leak in the system

 

[Walkerman]

I know I have a small leak have to add freon sometimes.
Right now the system is in the green.

 

[KennethS]

Sounds as if the low pressure switch is tripping due to low system pressure.

What are the high side and low side pressures when it’s running? That’s really the only way I know to diagnose AC issues. Anything else is just guessing.

 

[Chris]

After driving a few miles (it varies) ac comp. kicks out.
Changed low pressure switch. No Change..
TODAY: Drove it for 15 minutes and quit cooling.
After it quit I checked to see if the clutch was engaged. It was not.
I then disconnected the wire connecting to the LP switch and jumped it
with a wire. The clutch engaged and I kept the jump for 45 seconds.
Worked OK as long as I held the jump.
What is this telling me ???

It sounds like you're on the right track diagnosing the A/C issue. Since you've already replaced the low-pressure switch and found that jumping the switch allows the clutch to engage, it indicates that the problem might not be with the compressor or the clutch itself but rather with the circuitry that controls the low-pressure switch.

Even though you changed the low-pressure switch, if the refrigerant level is low, it may not be reaching the threshold to keep the clutch engaged. Checking the refrigerant level or having it topped off could be a good next step.

The new low-pressure switch could be malfunctioning. It may not be registering the pressure correctly. You might want to test it with a multimeter to ensure it’s functioning properly.

There could be a wiring issue somewhere in the circuit that connects the low-pressure switch to the A/C relay or the compressor. Inspecting the wires and connectors for corrosion, breaks, or shorts would be a good idea.

The relay for the A/C system might be failing. If it’s not sending the signal to engage the clutch when the system is working properly, replacing the relay could solve the issue.

If the A/C system is overheating, a thermal cutout could be kicking in and shutting down the compressor. Make sure the condenser is clean and free of obstructions.

Since you're able to manually engage the clutch by jumping the switch, you're narrowing down the issues to electrical components. Following these leads should help you identify the root of the problem. Good luck, and keep us posted on what you find!

 

[Walkerman]

It sounds like you're on the right track diagnosing the A/C issue. Since you've already replaced the low-pressure switch and found that jumping the switch allows the clutch to engage, it indicates that the problem might not be with the compressor or the clutch itself but rather with the circuitry that controls the low-pressure switch.

Even though you changed the low-pressure switch, if the refrigerant level is low, it may not be reaching the threshold to keep the clutch engaged. Checking the refrigerant level or having it topped off could be a good next step.

The new low-pressure switch could be malfunctioning. It may not be registering the pressure correctly. You might want to test it with a multimeter to ensure it’s functioning properly.

There could be a wiring issue somewhere in the circuit that connects the low-pressure switch to the A/C relay or the compressor. Inspecting the wires and connectors for corrosion, breaks, or shorts would be a good idea.

The relay for the A/C system might be failing. If it’s not sending the signal to engage the clutch when the system is working properly, replacing the relay could solve the issue.

If the A/C system is overheating, a thermal cutout could be kicking in and shutting down the compressor. Make sure the condenser is clean and free of obstructions.

Since you're able to manually engage the clutch by jumping the switch, you're narrowing down the issues to electrical components. Following these leads should help you identify the root of the problem. Good luck, and keep us posted on what you find!

THANK YOU

 

[KennethS]

It sounds like you're on the right track diagnosing the A/C issue. Since you've already replaced the low-pressure switch and found that jumping the switch allows the clutch to engage, it indicates that the problem might not be with the compressor or the clutch itself but rather with the circuitry that controls the low-pressure switch.

Even though you changed the low-pressure switch, if the refrigerant level is low, it may not be reaching the threshold to keep the clutch engaged. Checking the refrigerant level or having it topped off could be a good next step.

The new low-pressure switch could be malfunctioning. It may not be registering the pressure correctly. You might want to test it with a multimeter to ensure it’s functioning properly.

There could be a wiring issue somewhere in the circuit that connects the low-pressure switch to the A/C relay or the compressor. Inspecting the wires and connectors for corrosion, breaks, or shorts would be a good idea.

The relay for the A/C system might be failing. If it’s not sending the signal to engage the clutch when the system is working properly, replacing the relay could solve the issue.

If the A/C system is overheating, a thermal cutout could be kicking in and shutting down the compressor. Make sure the condenser is clean and free of obstructions.

Since you're able to manually engage the clutch by jumping the switch, you're narrowing down the issues to electrical components. Following these leads should help you identify the root of the problem. Good luck, and keep us posted on what you find!

This reads like it’s AI generated. There are several inaccuracies that are contrary to how the system actually operates.

 

[Walkerman]

This reads like it’s AI generated. There are several inaccuracies that are contrary to how the system actually operates.

I'm open to your ideas.

 

[Rickyd]

Download the 98 fsm from here- https://wranglertjforum.com/threads...ice-manuals-fsm-technical-documentation.4618/

And go down to 24-11 to start

 

[KennethS]

I'm open to your ideas.

OK. let me address a few of the things:

There is no circuitry that "controls" the low pressure switch. It is merely a switch that is closed when the system pressure the switch sees at the port is above approximately 25-28 psi, then the switch opens when the pressure drops below that point. When closed, the switch completes the circuit and allows voltage to the compressor clutch. If the wiring were open somewhere, the clutch would not engage when you jumper the switch at the connector.

I think you ruled out the relay that was mentioned since the system ran when you bypassed the low pressure switch, the same for the compressor overheating and the thermal cutout activating, as those would occur after the system was running for long enough to generate sufficient heat to activate the cutout.

The possibly of a faulty switch is valid, as is the possibility of low refrigerant charge. Both are easy to verify.

It appears that something is causing the low pressure switch to not close, but you need more data to determine what is causing that. It could be the switch itself, or the pressure the switch is seeing (which could be low charge, blocked port, stuck Schrader valve, etc).