2001 V70XC - Testing AC function over VIDA

[xHeart]

Another summer with warm temps have arrived. Has anyone used VIDA to fault trace and diagnose AC functions?

[yanga001]

So i just had an interesting saga. My previous p80 accepted a charge of R12A at 25-30 PSI to result in frothy cold. As such i attempted to charge the new system to that pressure. What i noticed is that the driver side would stay warm and passenger would be moderately cold. Checking with my code scanner my pressures remained below 1200 kpa on the high pressure side and it seemed to work in lower temperatures but failed on a 30+ day. What fixed it was charging the system up to 50 PSI when the compressor was activated as was advised on a few other forums.

At 1500kpa when the the system is operating i am now getting icy cold temperatures.

Now it will depend on the failure type and cause. If the compressor is not engaging then it may be a sensor tripped, shim, etc.

If auto does not work it may be a failed sensor in the CCM.

Hope this helps!

[firstv70volvo]

Another summer with warm temps have arrived. Has anyone used VIDA to fault trace and diagnose AC functions?

What's the problem with your AC? VIDA may be of some help with AC diagnostics but I doubt VIDA can tell you if the charge is just right or if there's air or moisture in the system. Best to use AC gauges, and thermal readings (infrared thermometer) in addition to checking for leaks, AC clutch operation and evacuating, recharging the system to get air/moisture out and the correct charge by weight.

[xHeart]

Thank you for your replies.

The AC blows cool air at AUTO for 10 minutes; takes the edge off in the cabin climate then blows warm/hot air.

I had removed the CCM unit for maintenance few month ago, and to clear out the fuzz balls around cabin temp sensor behind the tiny fan; which restored the CIRC switch function. The evaporator temperature sensor shows 2.54 Ohms ohm reading at room temp with multimeter dial at 20K; changes with hot and cold water dips.

There is a three-phase testing AC in VIDA which requires AC diagnostic software download part# soandso. Two summers ago, I used my harbor freight gauge to diagnose AC lines, and then recharged it with R-134a.

[firstv70volvo]

Thank you for your replies.

The AC blows cool air at AUTO for 10 minutes; takes the edge off in the cabin climate then blows warm/hot air.

I had removed the CCM unit for maintenance few month ago, and to clear out the fuzz balls around cabin temp sensor behind the tiny fan; which restored the CIRC switch function. The evaporator temperature sensor shows 2.54 Ohms ohm reading at room temp with multimeter dial at 20K; changes with hot and cold water dips.

There is a three-phase testing AC in VIDA which requires AC diagnostic software download part# soandso. Two summers ago, I used my harbor freight gauge to diagnose AC lines, and then recharged it with R-134a.

Have you used your gauge set to take a look at the high and low pressure yet? If it only blows cool and not cold air right from the start it would be good to know the pressure readings. When the air turns from cool to warm have you taken a look at the AC compressor clutch operation? If the AC clutch air-gap becomes too large from wear the clutch will start slipping or not engage at all, which can be seen when the inner part of the pulley area is no longer rotating. It's a little difficult but you can measure the air-gap with feeler gauge. I've seen clutch problems when the gap gets over 0.030 inch. If the air-gap is too large it can be adjusted by removing shims once the clutch pulley is removed.

Because the air is cool, not cold from the start it could be a system low on charge and why it would be good to get a look at the gauge pressures. Try to notice how the AC clutch engagement is cycling, does it cycle on and off too frequently or does it cycle off when the air goes from cool to warm? If the pressure becomes too low the AC compressor is shut off. If also shuts off if the pressure is too high.

I don't think this is your problem but the evaporator can freeze up if the evaporator sensor is bad, this would be a change in air flow out the vents and the air would be cold, not cool before the freeze up occurred.

[xHeart]

Have you used your gauge set to take a look at the high and low pressure yet? If it only blows cool and not cold air right from the start it would be good to know the pressure readings. When the air turns from cool to warm have you taken a look at the AC compressor clutch operation? If the AC clutch air-gap becomes too large from wear the clutch will start slipping or not engage at all, which can be seen when the inner part of the pulley area is no longer rotating. It's a little difficult but you can measure the air-gap with feeler gauge. I've seen clutch problems when the gap gets over 0.030 inch. If the air-gap is too large it can be adjusted by removing shims once the clutch pulley is removed.

Because the air is cool, not cold from the start it could be a system low on charge and why it would be good to get a look at the gauge pressures. Try to notice how the AC clutch engagement is cycling, does it cycle on and off too frequently or does it cycle off when the air goes from cool to warm? If the pressure becomes too low the AC compressor is shut off. If also shuts off if the pressure is too high.

I don't think this is your problem but the evaporator can freeze up if the evaporator sensor is bad, this would be a change in air flow out the vents and the air would be cold, not cool before the freeze up occurred.

Thanks again for your diligence.

I was able to measure the clutch gaps close to 12, 3, 9 o'clock positions last night - cold engine; the feeler 0.038 slides in without resistance where 0.040 takes some wiggle. Is this a large gap?

I'll hook up my PITTSBURG Manifold Gauge next for high and low pressure reading -- the gauge came with instructions.

[firstv70volvo]

Have you used your gauge set to take a look at the high and low pressure yet? If it only blows cool and not cold air right from the start it would be good to know the pressure readings. When the air turns from cool to warm have you taken a look at the AC compressor clutch operation? If the AC clutch air-gap becomes too large from wear the clutch will start slipping or not engage at all, which can be seen when the inner part of the pulley area is no longer rotating. It's a little difficult but you can measure the air-gap with feeler gauge. I've seen clutch problems when the gap gets over 0.030 inch. If the air-gap is too large it can be adjusted by removing shims once the clutch pulley is removed.

Because the air is cool, not cold from the start it could be a system low on charge and why it would be good to get a look at the gauge pressures. Try to notice how the AC clutch engagement is cycling, does it cycle on and off too frequently or does it cycle off when the air goes from cool to warm? If the pressure becomes too low the AC compressor is shut off. If also shuts off if the pressure is too high.

I don't think this is your problem but the evaporator can freeze up if the evaporator sensor is bad, this would be a change in air flow out the vents and the air would be cold, not cool before the freeze up occurred.

Thanks again for your diligence.

I was able to measure the clutch gaps close to 12, 3, 9 o'clock positions last night - cold engine; the feeler 0.038 slides in without resistance where 0.040 takes some wiggle. Is this a large gap?

I'll hook up my PITTSBURG Manifold Gauge next for high and low pressure reading -- the gauge came with instructions.

The gap you measured is on the high side, I don't know what the upper spec limit is but I've worked on several AC compressors that have had clutch engagement problems with a clutch airgap smaller than this, around .031 to 0.033 inch.
Because you're only getting cool air from your AC system initially I would suspect a low charge more than a clutch engagement problem. Typically when the airgap gets too large the clutch doesn't engage at all, the coil can't pull in the outside plate so the compressor isn't running and you just get warm/hot air inside the car. With your symptoms, the best thing for you to look at when the air goes from cool to warm is to see if the clutch is still engaged, when you detect warm air in the car check to see if the clutch is engaged, it should be, the inner part of the pulley should be spinning. If the clutch is engaged and the inside air is blowing warm then in this case it's a different problem and gauge readings will help diagnose.

[xHeart]

The gap you measured is on the high side, I don't know what the upper spec limit is but I've worked on several AC compressors that have had clutch engagement problems with a clutch airgap smaller than this, around .031 to 0.033 inch.
Because you're only getting cool air from your AC system initially I would suspect a low charge more than a clutch engagement problem. Typically when the airgap gets too large the clutch doesn't engage at all, the coil can't pull in the outside plate so the compressor isn't running and you just get warm/hot air inside the car. With your symptoms, the best thing for you to look at when the air goes from cool to warm is to see if the clutch is still engaged, when you detect warm air in the car check to see if the clutch is engaged, it should be, the inner part of the pulley should be spinning. If the clutch is engaged and the inside air is blowing warm then in this case it's a different problem and gauge readings will help diagnose.

Thank you!

Could this procedure include hooking up manifold gauge first and then "look at when the air goes from cool to warm is to see if the clutch is still engaged..."?

[firstv70volvo]

The gap you measured is on the high side, I don't know what the upper spec limit is but I've worked on several AC compressors that have had clutch engagement problems with a clutch airgap smaller than this, around .031 to 0.033 inch.
Because you're only getting cool air from your AC system initially I would suspect a low charge more than a clutch engagement problem. Typically when the airgap gets too large the clutch doesn't engage at all, the coil can't pull in the outside plate so the compressor isn't running and you just get warm/hot air inside the car. With your symptoms, the best thing for you to look at when the air goes from cool to warm is to see if the clutch is still engaged, when you detect warm air in the car check to see if the clutch is engaged, it should be, the inner part of the pulley should be spinning. If the clutch is engaged and the inside air is blowing warm then in this case it's a different problem and gauge readings will help diagnose.

Thank you!

Could this procedure include hooking up manifold gauge first and then "look at when the air goes from cool to warm is to see if the clutch is still engaged..."?

Yes, that would be even better to have the gauge pressure readings when the air temp changes. If the air temp changes consistently after about 10 minutes it would be good to monitor the hi/low pressure readings and watch the clutch pulley around the time of any change in air temperature. The gauge pressure readings will confirm if the clutch disengages for any length of time and could also detect if the clutch is slipping or some other problem but I think it's less probable the clutch is slipping.

[xHeart]

Thanks again for your diligence.

I was able to measure the clutch gaps close to 12, 3, 9 o'clock positions last night - cold engine; the feeler 0.038 slides in without resistance where 0.040 takes some wiggle. Is this a large gap?

I'll hook up my PITTSBURG Manifold Gauge next for high and low pressure reading -- the gauge came with instructions.

The gap you measured is on the high side, I don't know what the upper spec limit is but I've worked on several AC compressors that have had clutch engagement problems with a clutch airgap smaller than this, around .031 to 0.033 inch.
Because you're only getting cool air from your AC system initially I would suspect a low charge more than a clutch engagement problem. Typically when the airgap gets too large the clutch doesn't engage at all, the coil can't pull in the outside plate so the compressor isn't running and you just get warm/hot air inside the car. With your symptoms, the best thing for you to look at when the air goes from cool to warm is to see if the clutch is still engaged, when you detect warm air in the car check to see if the clutch is engaged, it should be, the inner part of the pulley should be spinning. If the clutch is engaged and the inside air is blowing warm then in this case it's a different problem and gauge readings will help diagnose.

Your comment above (in bold) made me look at my Feeler Gauge again; it is this gauge pictured below... therefore the gap I reported above was a reading error. The correct reading is "I was able to measure the clutch gaps close to 12, 3, 9 o'clock positions last night - cold engine; the feeler 0.38mm (0.015 in) slides in without resistance where 0.40mm (0.0157 in) takes some wiggle."