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Discussion Starter · #1 · (Edited)
Hey guys,

A coworker/friend of mine has an '02 V6 that recently started blowing hot air. Below is what happened, and what has been done:

1. During heavy rains, he hit a deep puddle on the right side of the street. It was near a drain, so presumably the passenger side of the vehicle was hit harder by the flood of water.
2. AC immediately stopped chilling, but the blower continued to work. Windows fogged almost immediately.
3. Over the next two weeks, the blower worked intermittently. Rain was still sporadic during this time. Blower has been working fine for the last few days since there hasn't been any rain, but still no cold air.
4. Compressor clutch has not engaged whenever spot-checked since the issue arose and I started talking to him about it.

Today, we did some brief parking lot diagnostics as I left work:

- Static pressure is good. Approximately 130 psi on both the high and low side with ~100 degree F ambient temps (parked outside in the sun all day).
- Jumped the low pressure switch (off the accumulator) with a paper clip. Nothing changed.
- Disconnected and jumped the high pressure switch off the discharge line (below the high pressure diagnostic port). No change.
- Turned off the car, disconnected the AC compressor clutch, and started it back up. 0V and infinite resistance on the wiring harness end (I couldn't conceive a safe way to test the resistance of the clutch while the car was running, or to apply 12V to it in order to cycle it manually).
- All relevant fuses listed in the owners manual were checked. #24 in the PDC in the engine bay, and #23 in the passenger compartment IIRC. I don't remember the exact fuse numbers now, but the PDC fuse was labeled as the "AC pressure switch" fuse, and the one in the passenger fuse box was labeled as being responsible for the AC compressor clutch and the defroster. Both fuses were fine.

Now, this leads me to believe it could be a faulty compressor clutch relay in the CCRM from what I've been reading (not sure if the CCRM also controls the blower - first time working on a Mustang).

What else can we check? I can't seem to find many other good diagnostic threads that detail these symptoms.

Thanks in advance!
 

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this car has a low and high pressure switch in series, you have to jump both at the same time.

The high press switch has two contacts and 4 wires.

You need to id the contact on the hi switch that is for fan and the contact for safety.

take both hi and lo pressure plugs off.
start car turn on a/c, test for power at low and Hi safety switch.

If you have power then you should be able to jump both, if you jump the fan switch the fan should come on.

The static pressure you measured does NOT mean you have the correct charge. remember that.
 

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Discussion Starter · #3 ·
this car has a low and high pressure switch in series, you have to jump both at the same time.

The high press switch has two contacts and 4 wires.

You need to id the contact on the hi switch that is for fan and the contact for safety.

take both hi and lo pressure plugs off.
start car turn on a/c, test for power at low and Hi safety switch.

If you have power then you should be able to jump both, if you jump the fan switch the fan should come on.

The static pressure you measured does NOT mean you have the correct charge. remember that.
Weird - I looked at the connector on the high pressure switch and although it is a 4-pin connector, it only has 2 leads.

I'm assuming the high/low switches close the circuit when appropriate conditions are met?

Also, does the CCRM have anything to do with the blower motor circuit, or only the AC clutch and auxiliary engine fan? His aux fan works fine.

With regard to the static pressure - definitely understood. The measurements I took merely indicate that there *appears* to be an appropriate charge in the system. We won't know for sure til we get the system to cycle.
 

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there must be another switch on the hi side.

one for fan and one for safety, if only two wires are used, which seems weird.

for the clutch to energize the low and hi safety must be closed.

low is normally open and hi is normally closed.

Indoor blower shouldn't be assoc with CCRM, but I'm not 100%, a wiring diagram would tell you.
 
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