AC low pressure switch location?

[Mustang Convert]

I’m having an AC issue with the air not blowing cold and honing in on it being a bad low pressure sensor. I have read that jumping it can be a good test. But I cannot find anything that shows where it is located on these cars. Does anyone have a photo?

I tested the fuses and relays and those aren’t an issue. I can get the compressor to engage and cold air to blow by jumping the compressor relay, but it won’t engage on its own without me jumping it. So I know the compressor works but it won’t engage independently.

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[ORRadtech]

I don't find any reference to a low pressure switch. Only to an A/C pressure transducer. Maybe this will help. Maybe not...

 

[Torinate]

How many transducers or pressure switches are there? High and low? Where are they both located? I see this as the low pressure sensor. Where’s the high pressure one?

Same issue as the OP.

 

[ORRadtech]

How many transducers or pressure switches are there? High and low? Where are they both located? I see this as the low pressure sensor. Where’s the high pressure one?

Same issue as the OP.

If you look at the highlighted phrase you'll see that the search term didn't include high or low. The search results only indicated one pressure transducer.
I'd highly recommend getting a Factory Service Manual. It has a very detailed description of the theory and operation of the A/C system as well as an extensive trouble shooting flow chart.

 

[Mustang Convert]

How many transducers or pressure switches are there? High and low? Where are they both located? I see this as the low pressure sensor. Where’s the high pressure one?

Same issue as the OP.

thank you. I’ve seen many people refer to having a failed low pressure switch replaced. Is this that same part? It seems to be on the high pressure side.

 

[Cobra Jet]

This image was found on American Muscle’s website of a 2016 GT where the location is being referenced as the A/C pressure switch:

https://www.americanmuscle.com/mustang-air-conditioning-pressure-sensor-904-612.html

 

[Mustang Convert]

Since that’s a 3-pin connector, which pins need to be jumped to test?

 

[mepawn]

Following this as i may have the same issue, admittedly could also have a leak just haven't tested yet.

 

[Torinate]

If you look at the highlighted phrase you'll see that the search term didn't include high or low. The search results only indicated one pressure transducer.
I'd highly recommend getting a Factory Service Manual. It has a very detailed description of the theory and operation of the A/C system as well as an extensive trouble shooting flow chart.

Interesting.

Typically a/c systems will have both a low pressure and also a high pressure sensor. One on the low side and one on the high side. Is the manual only showing 1 sensor? That’s the low side and I believe if you follow that line 18” toward the firewall is where the low pressure port to fill is located.

I agree. What 2 contacts to jump this to test the actual switch?

When I jump at the fuse box, system is cold++ so there is a charge in there. But the system never turns on. No fault codes either…

 

[ORRadtech]

Interesting.

Typically a/c systems will have both a low pressure and also a high pressure sensor. One on the low side and one on the high side. Is the manual only showing 1 sensor? That’s the low side and I believe if you follow that line 18” toward the firewall is where the low pressure port to fill is located.

I agree. What 2 contacts to jump this to test the actual switch?

When I jump at the fuse box, system is cold++ so there is a charge in there. But the system never turns on. No fault codes either…

I found it interesting as well that only one came up in the search. In another area of the FSM, where it refers to a non running compressor, it only lists the single transducer I showed as a possible cause. Well, among other things like low refrigerant, bcm, etc but only the one transducer.

I can't tell you which wires to jumper. But a DVOM might. I'd guess one wire is 12V, one is ground and the third is a 5V reference from the BCM (or whatever module turns it on).

Again, I recommend you get a FSM. It will answer questions like which wire. And, again, it does have an extensive troubleshooting flow chart for the A/C.

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