A/C Not working

[ctm78]

Last year my AC would work for about five minutes and then quit.

This year there is nothing at all. It doesn't look like the compressor clutch is even pulling in when I kick it on Max AC.

1. Is the clutch alone replaceable?
2. Is it a standard Taurus compressor, or is it a SHO specific one (five times as expensive.)
3. Any other suggestions?

Thanks.

 

[projectSHO89]

It is unlikely to be only your clutch based upon what you have said.

Unless you have the inclination to purchase your own guages so you can measure pressures, it is suggested you take the car to someone that has them.

Do not throw parts and/or money blindly into the A/C system.

Yor car may simply be low on refrigerant, there might be a faulty switch, or it might even have failed catastrophically. Guessing about it is unproductive. Proper tools and a sense of direction are needed.

Of course the compressor is SHO-specific. Think Ford would have done it any other way?

Steve

 

[rangerj]

The SHO has a Nippondenso 10P15F compressor. It is made to take the high RPMs of the SHO, and is only a few dollars more than other Ford vehicle compressors.

That having been said, Steve is correct. Do not start replacing parts without first doing the diagnostics. You can jumper the connection to the low pressure switch to see if the compressor will engage. If the compressor engages, then either the system is low on refrigerant charge, or the switch is bad.

If the compressor fails to engage, then it could be the clutch coil, which is replacable as a seperate unit, or there is a failure in the wires or connections of the A/C system.

There is a great article put together by the Utah SHO club and it has been posted numerous times on this forum. It walks you through the tests of the A/C electrical system, including the fuse, relay, wires, connections, and switches. Start your diagnostics there. Use the search feature.

Once you have a better idea as to what the problem is, or is not, then we can move toward solving it with the least amount of expense.

Look for black oily dirt around your A/C connections, behind the A/C clutch coil, on the front of the condenser (in front of the radiator). This is the sign of a leak. If your system is low on charge, then it has a leak, period. If you find the signs of a leak, then it is a good bet that that is why your compressor will not engage (low pressure due to leaked out refrigerant)

But, do the diagnostics suggested above so you can rule out other problems, AND become familiar with your A/C system. rangerj

 

[ctm78]

Got a hold of a 134 gauge, and the system has plenty of pressure.

Looking down the front of the engine, there are two wires going into the front of the compressor. Next step is to put 12 volts into the clutch connection to see if it pulls in (I'm assuming this compressor works like every other one out there---that being said, does anything on the SHO follow the standard?)

If it does engage, then I'll assume there is something wrong with a relay or something within the climate control system, otherwise it's the compressor.

Any faults to this logic? Or is it a mistake to apply conventional thinking to this car?

 

[projectSHO89]

How much is "plenty of pressure"? At least 45-50 psi is required to close the cycling switch.

If you have that much pressure, try jumpering the cycling switch. They do tend to go bad.

Also, check that plug on the clutch proper. I have seen them come loose due to broken retainer ears.

Steve

 

[shorage]

Do you mean OUNCES?

I hope you mean ounces.....45-50 PSI in an A/C unit?

 

[CheckerSHO]

I hope you mean ounces.....45-50 PSI in an A/C unit?

Static(system off) pressure should be at LEAST that for the compressor to even engage....it should be a good bit more than that if its fully charged and its pretty warm ambient temp.

 

[Rob94]

My system's static pressure is 65psi, at the low side. When the engine is running and the AC clutch is engaged, it drops to around 35-40.