ac compressor

[allan greyling]

my 96 compressor keeps clicking on the off within a few seconds tries to produce cold air but compressor does not stay on long enough. put a guage on it and it said freon level is good. any help???

 

[Silvapain]

pull the low pressure switch connector (located on top of the drier right in front of the coolant reservoir on the passenger front side of engine bay), and use a paper clip to jumper the wires. If the A/C compressor turns on and stays on, then the car is getting a signal that freon pressure is low. It's usually a result of low freon level, but could be a bad low pressure sensor. If the A/C compressor does the same thing whether the switch is jumpered or not, then reconnect and repeat the test with the high pressure switch, located right next to the compressor on the high side line to the condensor down between the radiator and the engine.

 

[allan greyling]

great thanks tried it and it stayed on so i put the gauge back on still a little low on freon put more in remained cool but not very cold believe i may have a small leak some where.

 

[projectSHO89]

Of course you have a leak, that is why it is undercharged!

Compressor short-cycling is ALWAYS due to a low refrigerant charge.

Low-side only gauges are not adequate to accurately measure the charge in the system. Get a manifold set and do it right or take it to someone who is properly equipped and is knowledgeable about the system

Steve

 

[Silvapain]

There are leak test kits available. It's a fluorescent dye that you put in the lines, and a light and yellow glasses that you use to find the leak. I recommend just buying an A/C O-ring kit as well, and replace all the O-rings that you can. Off the top of my head, there are:

1- into Evaporator at firewall
1- out of Evaporator at wall
1- at dryer
2- at manifold on Compressor
1- into condenser
1- out of condenser

You will need a set of A/C / Fuel Line disconnect tools to get to some of the O-rings. Also, the two at the firewall are nearly impossible to get to unless the engine is out of the car IIRC. Good Luck.

 

[93rev2sev]

Compressor short-cycling is ALWAYS due to a low refrigerant charge.

Steve

[Hijack in progress!!]
What if your oriface tube is restricted(more than normal)? Will that short cycle the compressor? The reason I ask, is because I replaced all the lines and compressor(except oriface tube) on my 93 and it's fully charged and short cycleing...still blows cold but feels like the compressor is laboring. I was thinking that the oriface tube is more of a restriction than it should be. Causing the low side to be too low...click!

If I'm right, I'll want to swap out that oriface tube right away, huh?

 

[naval-avi8or]

[Hijack in progress!!]
What if your oriface tube is restricted(more than normal)? Will that short cycle the compressor? The reason I ask, is because I replaced all the lines and compressor(except oriface tube) on my 93 and it's fully charged and short cycleing...still blows cold but feels like the compressor is laboring. I was thinking that the oriface tube is more of a restriction than it should be. Causing the low side to be too low...click!

If I'm right, I'll want to swap out that oriface tube right away, huh?

How/why did you replace all the line and not the orifice tube. One its built into one of the line and second it's cheep.

On the other hand if the compressor is laboring, did you add the correct amount of oil. I'll assume you did a R-134 conversion and as stated in an earlier post you need a good manifold set and also need to know what your doing as R-134 is not nearly as forgiving as R-12. Just a small over servicing and the head pressure will sore thru the roof causing cycling. The amount of freon serviced is based on temp/head pressure and not the capacity/conversion charts.

You may also just need new cycling and/or high pressure cut off switch which is spacific to frean so if they are the old R-12 they should be replaced.

 

[Silvapain]

How/why did you replace all the line and not the orifice tube. One its built into one of the line and second it's cheep.

As in "tweet tweet"?

 

[naval-avi8or]

As in "tweet tweet"?

As in DOH!

Disregard the R-134 I was just looking in the service manual and it show R-134a. I thought it was a 94 and up thing.

 

[93rev2sev]

I had a 134a oriface tube on hand. It came from a working A/C system.

I replaced the line with a known good used 134a line.

Yes I converted.
Yes I added the right amount of oil...I think.


I basically took all the known good parts from a donor 95 SHO and replaced whatever looked beat down(or didn't fit into an MTX). This included all of the hoses except the one with the oriface tube.

I installed the 95 lines into my 93...I can't remember which pressure switch I used...probably the one from the 95...

The 95 had 2 switches... one on the coffee can(at the firewall) and one near the radiator support.

The 93 only had the one switch...on the coffee can under the battery(MTX). I left the other switch screwed into the line from the 95...unplugged...cause there was no connector for it...as far as I could tell.

At idle, it works great...at higher RPMs it cycles. It also screeches the belt for a split second at RPMs above 3000.

I was guessing the OLD ASS oriface tube from the 95 was clogged, causing a bigger restriction in the system. And in turn, causing the compressor to labor and too large of a pressure differential causing the cycling.

 

[naval-avi8or]

Yes I added the right amount of oil...I think.

You can't think you did you have to know you did. When replacing parts you have to replace the correct amount oil direcrtly into that part. Here's the FORD procedure.

Adding Refrigerant Oil

The FS-10 and 10P15F A/C compressors use a unique high-quality refrigerant oil (E73Z-19577-A), Motorcraft Part Number YN-12 or an equivalent, refrigerant oil meeting Ford specification ESH-M2C31-A2. An oil charge of 207 ml (7 oz) is used in a new FS-10 system and 240ml (8 oz) is used in a new 10P15F system. It is extremely important that only the specified type and quantity of refrigerant oil be used in the compressors. If there is a surplus of oil in the system, it will circulate with the refrigerant, reducing the cooling capacity of the systems. Using too little oil or oil not meeting the Ford specification will result in poor lubrication of the A/C compressors.

When replacing a component of the refrigerant system, the procedures in this Section must be followed to ensure that the total oil charge in the system is correct after the new part is installed.

When the A/C compressor is operated, oil gradually leaves the A/C compressor and is circulated through the system with the refrigerant. Eventually, a balanced condition is reached in which a certain amount of oil is retained in the A/C compressor and a certain amount is continually circulated. If a component of the system is removed after the system has been operated, some oil will go with it. To maintain the original total oil charge, add oil as required to the new replacement part.

The procedures for replacing oil are as follows:


During A/C Compressor Replacement

A new service replacement FS-10 A/C compressor contains 207 ml (7 oz) of refrigerant oil. A new 10P15F replacement A/C compressor contains 43ml (1.4oz) of YN-12 refrigerant oil or equivalent. Prior to installing the replacement A/C compressor, drain the refrigerant oil from the removed A/C compressor into a calibrated container. Then, drain the refrigerant oil from the new A/C compressor into a clean calibrated container.

l If the amount of oil drained from the removed A/C compressor was between 90 and 148 ml (3 and 5 oz), pour the same amount of clean refrigerant oil into the new A/C compressor.

l If the amount of oil that was removed from the old A/C compressor is greater than 148 ml (5 oz), pour 148 ml (5 oz) of clean refrigerant oil into the new A/C compressor.

l If the amount of refrigerant oil that was removed from the old A/C compressor is less than 90 ml (3 oz), pour 90 ml (3 oz) of clean refrigerant oil into the new A/C compressor.

NOTE:
Replacement of the suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.


During Component Replacement

When replacing other components of the air conditioning system, measured quantities of the specified refrigerant oil should be added to the component to ensure that the total oil charge in the system is correct before the system is operated.

Clean refrigerant oil should be poured directly into the replacement components as follows:

NOTE:
Replacement of the suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.

l A/C evaporator core: add 90 ml (3 oz).

l A/C condenser core: add 30 ml (1 oz).

l Suction accumulator/drier: Drill a 12.7mm (1/2-inch) hole in the suction accumulator/drier body and drain oil from suction accumulator/drier through that hole. Drain existing oil from new suction accumulator/drier then add same amount of oil removed, plus 60 ml (2 oz) of clean refrigerant oil to new suction accumulator/drier.

If any other component such as an A/C evaporator core orifice or a hose is replaced, no additional refrigerant oil is necessary unless a hose bursts with a fully-charged system. Then, the addition of 60 ml (2 oz) of refrigerant oil may be necessary with the amount to be determined by the technician. The suction accumulator/drier should also be replaced under these circumstances. Refer to «Section 12-00».

In effort to avoid the use of CFC refrigerants that may harm the ozone layer of the atmosphere, Ford Motor Company has introduced a new refrigerant system on some 3.0L Taurus vehicles that requires the use of a non-CFC based refrigerant known as R-134a. This new type of refrigerant has many of the same properties as R-12 and is similar in form and function. However, R-134a is a hydrofluorocarbon (HFC)-based refrigerant while R-12 is a chlorofluorocarbon (CFC)-based refrigerant. Because of the absence of chlorine in its molecular structure, the use of R-134a refrigerant will not have any harmful effects on the ozone layer.

CAUTION:
Do not add R-12 refrigerant to an A/C system that requires the use of R-134a refrigerant. Do not add R-134a refrigerant to an A/C system that requires the use of R-12 refrigerant. These two types of refrigerant should never be mixed. Doing so may cause damage to the A/C system.

NOTE:
R-134a A/C systems can also be identified by a gold-colored A/C clutch and green colored O-ring seals used throughout the system.

In order to determine which type of A/C system a particular vehicle has, inspect the A/C system major components and refrigerant lines. If the system components have yellow R-134a NON-CFC tags as shown below, it is an R-134a system requiring the use of R-134a refrigerant.



CAUTION:
R-12 and R-134a components are not interchangeable. Do not replace components from an R-134a system with components for an R-12 system and vice versa. Mixing components from these two types of systems may cause component failure and damage to the A/C system.

The major components of R-134a A/C systems are similar to those used previously on Ford R-12 A/C evaporator core orifice type systems. R-12 and R-134a components are similar in design and function. As a result, all Removal and Installation procedures outlined for R-12 components can be used for R-134a components.

 

[allan greyling]

ok well been a couple of days now and the ac is still working not very cold but does blow quite cold. I am waiting for this weekend my father in law has some proper gauges so we are going to hook it up and see. Thanks for all the advice...

 

[projectSHO89]

[Hijack in progress!!]
What if your oriface tube is restricted(more than normal)? Will that short cycle the compressor? The reason I ask, is because I replaced all the lines and compressor(except oriface tube) on my 93 and it's fully charged and short cycleing...still blows cold but feels like the compressor is laboring. I was thinking that the oriface tube is more of a restriction than it should be. Causing the low side to be too low...click!

If I'm right, I'll want to swap out that oriface tube right away, huh?

A restricted o-tube will cause a symptom that may resemble short-cycling, but your gauges will tell the difference.

When a low charge condition is present, the low side will bounce between the cycling switch limits while the high side will bounce upwards with each compressor on-cycle.

A restricted o-tube will usually not cause the frequency of the cycling to be so short. Additionally, the low side will not bounce upwards as quickly (due to the reduced rate of flow back to the accumulator via the evaporator. Additionally, the high side readings will tend to be on the low side. A check of the evaporator inlet and outlet tubes during operation will show that the outlet is warm. Also, when the system is shut off, it takes much longer for the high and low sides to equalize than it would with a properly flowing o-tube.

Verify your static pressure, it should be between 90-110 psi at typical under hood temps. This will ensure you have charge level that is in the ballpark.

Steve

 

[naval-avi8or]

A restricted o-tube will cause a symptom that may resemble short-cycling, but your gauges will tell the difference.

When a low charge condition is present, the low side will bounce between the cycling switch limits while the high side will bounce upwards with each compressor on-cycle.

A restricted o-tube will usually not cause the frequency of the cycling to be so short. Additionally, the low side will not bounce upwards as quickly (due to the reduced rate of flow back to the accumulator via the evaporator. Additionally, the high side readings will tend to be on the low side. A check of the evaporator inlet and outlet tubes during operation will show that the outlet is warm. Also, when the system is shut off, it takes much longer for the high and low sides to equalize than it would with a properly flowing o-tube.

Verify your static pressure, it should be between 90-110 psi at typical under hood temps. This will ensure you have charge level that is in the ballpark.

Steve

You got the info for HI/LOW side KEOR @ idle (I'm getting 30-40 low side and 250-300 High side @ 103 deg OAT). I know I still have a small issue as my cooling fans cycle on and off when MAX AC is selected instead of staying on. I think it maybe due to the stepdown resistor.

 

[naval-avi8or]

Disregard I found my book.