Write-Up: AC Compressor & Clutch Replacement

Yes, great write-up David, thanks very much for that info, we will all be facing this one sooner or later.

Glad to help! Heres a rough break down of costs
New Delphi compressor $196 shipped (rockauto)
New ACdelco Accumulator $29 shipped (rockauto)
Variable Orifice (factory air) $35 (Advance). You can also get a standard orifice for about $3
Pag oil $7 Autozone
UV dye $9 Advance
I charged it myself using a friend's gauges and vac pump, so the 134a cost $8 a can at walmart. I needed 4 cans as the gauges leaked, you usually only need a little over 2 cans.
A lot cheaper to do yourself. I spent a total of $269 on parts without the refrigerant. A shop would probably charge about $120 to charge it providing no issues were found, that's just a guess. A place near me is charging $99 to charge with 1lb of refrigerant included, our cars need 2lbs.

Exactly what I was thinking... Thank you! Here's a _+_ for you.

My only comments would be:
- Wow, great deal on the drier!
- Don't anyone buy the NON-variable orrifice-valve...

By the way, I totally understand the paranoia, but I'm very glad that your
dye purchase was "useless"...

The variable orifice was well worth the cost. When my AC did work before, at idle it was barely worth having on, only when driving was the AC cold enough to use. One interesting note about the drier. The box was an AC delco, bu the drier was a delphi. Further confirming they are one in the same company.

moldymac wrote:

Glad to help! Heres a rough break down of costs
New Delphi compressor $196 shipped (rockauto)
New ACdelco Accumulator $29 shipped (rockauto)
Variable Orifice (factory air) $35 (Advance). You can also get a standard orifice for about $3
Pag oil $7 Autozone
UV dye $9 Advance
I charged it myself using a friend's gauges and vac pump, so the 134a cost $8 a can at walmart. I needed 4 cans as the gauges leaked, you usually only need a little over 2 cans.
A lot cheaper to do yourself. I spent a total of $269 on parts without the refrigerant. A shop would probably charge about $120 to charge it providing no issues were found, that's just a guess. A place near me is charging $99 to charge with 1lb of refrigerant included, our cars need 2lbs.

Those are about the same numbers I came up with when looking in to it earlier.

Great write up Dave, this will be very helpful to me hopefully next week when I do this. I'm just waiting for the dryer and orifice tube to come in.

You had mentioned you didn't need the assorted pack of o-rings but in the write up you replaced a lot of them. Did you have some lying around or did they come with the compressor and dryer when you purchased them?

Thanks!

VJD2 wrote:

Great write up Dave, this will be very helpful to me hopefully next week when I do this. I'm just waiting for the dryer and orifice tube to come in.

You had mentioned you didn't need the assorted pack of o-rings but in the write up you replaced a lot of them. Did you have some lying around or did they come with the compressor and dryer when you purchased them?

Thanks!

The new compressor and dryer came with O-rings. The compressor actually uses a washer with a seal built in instead of O-rings. One thing I forgot to mention was the O-ring for the pipe that the orifice tube is in. The assorted pack did not come with one the right size. I ended up having one from another project. It looked like it could probably have been reused but I don't like to take chances with high pressure seals.

Ok so I just have to source that one o-ring.

I went through three AC compressor clutches before I finally replaced the compressor. Luckily it was all under warranty. The AC compressor was leaking oil internally, and it was extremely hard to turn by hand. Everyone including my mechanic swore it was the clutch until we took an extremely close look. The clutch would engage if you took a long stemmed screw driver and manually engaged it. Just save yourself the headache and replace the whole assembly. These things seem to go bad on these cars. Cost me about $400 to do it.

My best guess - you are probably leaking freon from the high milage compressor. But it's certainly possible to have other components leak.

Interesting, thanks, guys. It seems like I'm due for a recharge. Any idea what size can I would need to use for our system?

if you have an autozone near by rent the A/C manifold gauge set. The little gauges that comes on the cans are not very accurate.
If you do indeed need refrigerant then you can add a 12oz can at a time until you are at the proper pressure. some cans are just pure refrigerant while other are a mix of stop leak, oil and 134A. If you get the pure stuff it wouldn't hurt to add some more compressor oil too. i believe our cars take the PAG 150 HV oil but you may want to double check that. You can get a really small can of the oil and add it the same way you add the 134A can.

Mr.Riviera wrote:

if you have an autozone near by rent the A/C manifold gauge set. The little gauges that comes on the cans are not very accurate.
If you do indeed need refrigerant then you can add a 12oz can at a time until you are at the proper pressure. some cans are just pure refrigerant while other are a mix of stop leak, oil and 134A. If you get the pure stuff it wouldn't hurt to add some more compressor oil too. i believe our cars take the PAG 150 HV oil but you may want to double check that. You can get a really small can of the oil and add it the same way you add the 134A can.

On another thread on this site somebody explained why you *don't* get the refrigerant with stop-leak. Might want to search for it.

Albertj

When there is not enough pressure in the system, the clutch will not engage thus no AC. I'm guessing that was causing yours not to work from time to time. Try connecting a recharge kit to the low pressure port for the cheap end fix or get the whole system vac'd and recharged professionally. You might have a leak somewhere.. hard to say with high miles.

DEMonte1997 wrote:

When there is not enough pressure in the system, the clutch will not engage thus no AC. I'm guessing that was causing yours not to work from time to time. Try connecting a recharge kit to the low pressure port for the cheap end fix or get the whole system vac'd and recharged professionally. You might have a leak somewhere.. hard to say with high miles.

if you are going to go the recharge kit route, there is a kit you can get (last I saw one was at autozone) that has a dye in the refrigerant so that leaks can be spotted with a UV LED light (included with the kit).... sometimes all you need do is re-tighten the leaky fittings being careful not to overtorque them. You have to use your judgement--I am not saying go do that instead of taking it to a shop, I am saying I've seen such things available and it occurred to me you might not have so I'm sharing.

Today I checked pressure in the system. A gauge on the low-side showed 45 PSI @ 80ºF with car running and AC on. According to the instructions, that is in the middle of the normal range I should see at 80ºF. I'm going to assume there isn't a leak and monitor the voltage to the clutch with a lamp. Stay tuned...

Go to Harbour Freight ,and for $20 you can buy a little vac to remove all the old refrigerant

Wired a test lamp today (fine leads tapped into plug terminals, no cutting) and found no voltage going to AC clutch when AC is turned on. Trouble is, I haven't been able to get it to work 'properly' since this morning, so cannot confirm 100% that the clutch isn't going bad, but it's a good sign to see the lamp not lighting, indicating this is most likely electrical: a wiring issue, fuse, or relay. Now need to trace the wiring and find where the fuses and relays are (fuses in front of cabin look good).

double check the wiring isn't fouled by oil,if it is it will intermittently short out

Thanks. Moving the test light upstream to a location above or behind the engine should rule out that issue. I don't have my manuals with me. Does anyone offhand know where the wiring to the clutch is routed to? Does it go to a relay under the rear seat, or just to the fuse box up front?

UPDATE: found a way to activate the clutch, allowing the AC system to operate. Using the climate control in automatic mode, I lowered the desired temperature down to 60º (it's minimum value). This caused the clutch to turn on. I made sure to confirm the test lamp was not illuminated before turn-on, and did light with clutch engaged. The AC blew ice cold air. This means the clutch, compressor, and all wiring, relays and fuses are probably working correctly. Now I'm almost convinced it's the climate control module.

AA wrote:

Thanks. Moving the test light upstream to a location above or behind the engine should rule out that issue. I don't have my manuals with me. Does anyone offhand know where the wiring to the clutch is routed to? Does it go to a relay under the rear seat, or just to the fuse box up front?

UPDATE: found a way to activate the clutch, allowing the AC system to operate. Using the climate control in automatic mode, I lowered the desired temperature down to 60º (it's minimum value). This caused the clutch to turn on. I made sure to confirm the test lamp was not illuminated before turn-on, and did light with clutch engaged. The AC blew ice cold air. This means the clutch, compressor, and all wiring, relays and fuses are probably working correctly. Now I'm almost convinced it's the climate control module.

Rock Auto sells the in-cabin air temp sensor as a separate part and it is not pricey.

I wonder if maybe it's busted.

See that module forces the AC on when you turn it down to 60 no matter what the sensor says. If the thermistor in the sensor is bad it might be "telling" the climate module that it's cold in the cabin so the AC won't come on unless you turn the temp all the way down to 60 F.

You might want to see if the heat does not come on until you turn the temp up to 90 (that forces it on).

...anyway I'd consider getting a junkyard sensor if handy and check that before assuming the HVAC control head crapped out... maybe just wishful think on my part...

Albertj

Good thoughts, but I don't think it's the in-cabin sensor. My reasoning is, the sensor doesn't know the temperature of the AC vent air. It can't, because it only reads cabin air temp. AC vent air temp should remain constant, right? What the cabin sensor does is tell the climate control how much AC vent air to blow into the cabin to cool it down, until it reaches the cabin air target temp. Here are the clues:

• When the AC is acting up (turned "on" but clutch not engaged), the blower motor still wants to blow AC air, because it has no way of knowing the vent air isn't cool. It thinks it needs more, so just blows harder the hotter the cabin gets. This would indicate the sensor is sending feedback to the climate control, imo.

• When the AC is working correctly (clutch engaged), the system works perfectly, even if I raise the cabin target temperature back to being close to actual cabin air temp. It will blow harder the lower I set the temp, and gets softer as the cabin cools. The climate control would not be able to operate this way unless the in-cabin sensor is doing its job.

The irony is, I ordered the climate control unit by mistake from Ed Morad years ago, when trying to order the blower control module. I seem to remember the climate control being a bit pricey.

I have one more thing to check...

AA wrote:

Good thoughts, but I don't think it's the in-cabin sensor. My reasoning is, the sensor doesn't know the temperature of the AC vent air. It can't, because it only reads cabin air temp. AC vent air temp should remain constant, right? What the cabin sensor does is tell the climate control how much AC vent air to blow into the cabin to cool it down, until it reaches the cabin air target temp. Here are the clues:

• When the AC is acting up (turned "on" but clutch not engaged), the blower motor still wants to blow AC air, because it has no way of knowing the vent air isn't cool. It thinks it needs more, so just blows harder the hotter the cabin gets. This would indicate the sensor is sending feedback to the climate control, imo.

• When the AC is working correctly (clutch engaged), the system works perfectly, even if I raise the cabin target temperature back to being close to actual cabin air temp. It will blow harder the lower I set the temp, and gets softer as the cabin cools. The climate control would not be able to operate this way unless the in-cabin sensor is doing its job.

The irony is, I ordered the climate control unit by mistake from Ed Morad years ago, when trying to order the blower control module. I seem to remember the climate control being a bit pricey.

I have one more thing to check...

I get it now that I see your addl detail. Probably not the temp sensor.

You might be able to get a head unit from a u-pull; isn't the one from the same vintage Park Ave the same?

Update: the problem was eventually diagnosed as a failed IAT Sensor. See this thread for resolution: https://rivperformance.editboard.com/t8404-code-p0113-intake-air-temperature-sensor-iat#130796

Aaron, i guess i dont have as good of luck as you do with a/C systems.
My compressor decided to finally die today. It has been making a clicking noise because i got debris in the system and the check valve wasnt metering fluid correctly. Now it just spins but the compressor is so torn up inside it doesnt compress the refrigerant, assuming there is still some in there. Drove home in stop and go traffic for an hour and the temp gauge read 101° the entire time. (least i got a little more tan )

I know i need to replace the compressor, orifice tube and dryer/receiver. Are there any other components that need/should be changed when rebuilding a A/C system?
Which compressor does everyone recommend? (keep in mind i live in FL) there is a pretty big price difference between the seasons name brand and denso. ($166 vs $330)

Is it as simple as vac'ing the system, changing the parts and refilling it with R134A and oil? Anything i should watch out for?

Last question: where is the orifice tube located? i have looked but cant find anywhere that it would go.