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Sorry, I am going to step back and echo the advice of 96 Black in post 2.
Going into this , not understanding diagrams , not fully understanding instructions could lead you down the wrong path and your probing, jumping could damage components.
The are, as I said ,many engine, drivetrain issues that can cause the PCM not to command AC even though the AC system is fine.

Punishem1990, good luck

Fred, read back , and look at the diagrams .The PCM gets the pressures for the pressure transducer and works from that.
There is no high pressure cut out switch on the compressor.
 

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I can see how it works, but I do not know the location of the AC pressure cycling switch, and the refrigerant pressure switch. He gets power to the AC clutch relay (ckt 459 and 141), but not to the clutch solenoid (ckt 59). I do not know if he has a good ground for the activating coil of the clutch relay. The wire in ckt 59 comes from the relay, and goes to the coil of the clutch. If it the clutch is not activating, either the relay is not activating, or the wire to the clutch is an open. From what I see, it could be a burned wire, or a bad ground for some aspect of the relay.
 

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The AC pressure cycling switch or the refrigerant pressure switch could stop the system from working. I am going to guess the pressure cycling switch is the one on the accumulator. It tested good, He needs to find the refrigerant pressure switch to clear that possibility.
 

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Discussion Starter #44
I found it by the coolant tank on the ac line it has three pins. I'm only getting power to one of the pins
 

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One is power (ckt 416), one is ground (ckt 422), and one is a signal to the computer (ckt 380). The map sensor is also involved with the power ckt (422) to the computer internally.
 

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Its a transducer, not a ☆¤《《¤ switch.

5 volt, ground, 0 to 5 volt output to the PCM.
Now he found it , whats he going to do wirh it ?
Unless you have a jumper harness and the output chart from the FSM , what are you going to do??.
Jump the wrong thing and you could hurt the PCM sensor out put.
 

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I feel like a dummy right now sorry. Yes I have continuity
I have a hard time understanding wiring diagrams
.....Btw what is fsm?
OP, I did not, and you should never either, confuse ignorance and inexperience with 'dummy' or unintelligent. It didn't take much to see you're genuinely willing to get in there and dice it up to get to the solution. I saw just as clearly you aren't properly armed yet to stack the deck in your favor. My recommendation for the FSM (Factory Service Manual) was contributed admirably by 95- and Fred, but the best reason to still get one is to read it - and then read it again - and then again 20 more times to get the hang of these wiring diagrams that intimidate you so far.

Patience and search are gonna be your success. Pay your dues and get to a trusted shop like I suggested and watch like a hawk and use what you see on the next 500 similar diagnostic exercises eh.
 

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Discussion Starter #49
I appreciate all you guys help. Maybe I'll just bite the bullet and either keep riding with the 460 ac or take it to a shop
 

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Hang around long enough and the value of every thread eventually presents itself.

I learned a new spelling of ****ing: ☆¤《《¤
 

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Discussion Starter #53
Well guys I think I found the issue. It only has 20 psi of freon in it on the low side. Do you all think this could be the problem? It was 80 degrees today as well. I love in south Florida so it gets hot down here
 

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Well, i posted the pressures.

If you are speaking of ac off, there is no real number.

The very old rule of thumb is was everything off, static pressure on both sides roughly surounding air temp in Fahrenheit

Gives you an idea but I would not use that as a filling target .

Bit of a wild goose chase as your very first post said the pressures were good.
 

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I would not power the potentiometer (not a switch). I would test it to see what the output is. You can put probes in the connector, and check it with a meter.
 

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duplicate
 

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Sorry to jump in too. Hope I don't confuse things worse.

The switch on the dryer (the silver metal cylinder on the fender by the fuse box) is the low pressure cycling switch. This switch needs a minimum pressure to close. 20psi on the low side steady state will not close it! How do you know the freon is properly charged?

To explain further for those who don't like schematic diagrams and want to understand the system at a basic level (trying to keep it as non-technical as possible here):

To simplify the circuit, you need to have the low pressure cycling switch closed and the dash switch set to AC before the PCM (engine computer) will command the relay to close to engage the clutch. To test if the pressure cycling switch is closed, unplug it, then use your meter on continuity and test the switch (male spades) on the dryer. You should get continuity all the time in a steady state (AC compressor not running, engine turned off). If this test fails, then your freon charge is too low. You said 20psi, yep, that's too low. Steady state, AC off, clutch off, engine off, the pressure on the low and high sides should equalize to and read pretty high (over 80psi) at the low side port. Well beyond the pressure needed to close the switch.

Once the compressor is running, the vacuum side of the compressor will draw down the pipe going to the dryer. This is the intake to the compressor. At the same time, the high side will increase in pressure. This is the output from the compressor going to the coil. There is a chart in the service manual that indicates the nominal low and high side pressures at specific temperature and humidity while the clutch is engaged.

So... once the compressor draws down the low side so far (pressure drops), the cycling switch opens and compressor shuts off. This is to prevent freeze up. But this switch should only open once pressure gets low enough. Once the compressor is off for a period of time, the pressure equalizes in the dryer (builds back up above to 20-40psi), the cycling switch closes, the relay is energized, the clutch turns on, and the compressor runs for a while. The cycle continues. On a hot day, at low RPM, with proper airflow, the system pressure may never drop enough to cycle the compressor, in which case the switch stays closed and it never cycles, the compressor just runs constantly.

The high pressure switch (the 3-pin switch) on the pipe by the battery is not a switch. It's a variable-resistor sensor that gives the PCM a reading of high-side pressure. There is no clutch power going through this sensor. It is low-voltage PCM signals only. The PCM uses this reading to sense over-pressure (high head pressure) and will command the secondary fan to turn on once this pressure reaches a certain point. For example, sitting in traffic on a hot day without enough airflow. The primary fan is always commanded to turn on as soon as the PCM detects the aforementioned cycling switch has closed.

I hope this helps understand the system. It's quite an easy system to diagnose electrically once you understand how it works:

AC dash switch -> pressure cycling switch -> PCM
PCM -> Clutch relay -> Clutch

Finally, the pressures must be properly tested using a R-134a manifold gauge set (Harbor Freight sells one). The pressures must be compared to ones in the FSM (Factory Service Manual) for proper operation. One-time use gauges that come with freon cans, or gauges with color codes and not PSI readings cannot be relied upon... ever... for testing these systems.

(Note that I pulled this info from memory, it's not a substitute for actual facts and troubleshooting as per the FSM)
 
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