• Hint: Use a descriptive title for your new message
    If you're looking for help and want to draw people in who can assist you, use a descriptive subject title when posting your message. In other words, "2008 LaCrosse" isn't going to indicate to anybody that you need help. However, "Need help with my 2008 LaCrosse" will. Be as descriptive as you can. Please use common sense... This message can be closed by clicking the X in the top right corner.

A/C clutch not engaging

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
On my 97 LeSabre (manual AC), the A/C clutch fails to engage. Here's what I've done so far:

1) 12V directly to the clutch does engage the compressor clutch.
2) With engine running, AC on MAX, voltage at the AC relay is 12V but anywhere from 0.5V to 3V at the compressor clutch connector.
3) Engine running again, AC on MAX, AC relay jumpered so solid green wire at relay end has 12V. The green wire at the compressor end only has 0.5 to 3V.

I have not verified refrigerant pressures, but I figured that by jumping the AC relay that should have forced the clutch to engage. According to the wiring diagram, the green wire is continuous from the relay to the clutch, with the exception of one connector at C101, so I cannot see any reason for a loss of voltage.

What am I missing?
 

DonP

Full Member
897
7
18
VA
Buick Ownership
2017 Buick LaCrosse.
There may be a low pressure switch in the circuit that prevents the A/C clutch from engaging if the system is low on charge.
 

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
That may be true, except that I have tried to force the compressor on by jumpering pins 30 and 87 of the relay which would override anything like the low pressure switch.
 

HotZ28

Full Member
7,098
344
83
Buick Ownership
1996 Roadmaster Limited Collectors Edition 58k - 1996 PAU
Obviously, you need to find out why the green wire is not delivering 12v to the clutch. IIRC, that wire (green) goes through a harness that is routed across the engine and under the alternator. The wire shielding & insulation may be broken & cracked in that area.
______________________________
 

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
Not surprisingly, everyone was right. I just needed HotZ to push me to finish the electrical diagnosis.

I couldn't find my usual test probes I use to probe female end connectors, so I used a couple of mini blade screwdrivers and an alligator lead to jumper the relay. The poor electrical connection was my screwdriver probe.

Once I got the compressor running, the low pressure side did not even begin to cool. I'm pretty sure I lost my refrigerant. I'll need to find some one with guages, and probably a sniffer.

Thanks for all the help!
 

HotZ28

Full Member
7,098
344
83
Buick Ownership
1996 Roadmaster Limited Collectors Edition 58k - 1996 PAU
Once I got the compressor running, the low pressure side did not even begin to cool. I'm pretty sure I lost my refrigerant. I'll need to find some one with guages, and probably a sniffer.
I would first suspect the front compressor seal as the area of the leak. This is fairly common with a 17-yr old compressor. If you do find it leaking in that area, I would suggest replacing the compressor with a NEW Delphi compressor from RockAuto. Of course, in order to get a warranty on any compressor, you would need to replace the accumulator, orifice tube, evacuate, & flush the system and have documentation that those items were all done by a reputable licensed A/C shop.
 

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
That would be the proper way to fix it. Up here in Canada it will cost several hundred in labor by the time they suck it down, flush, then fill. All for a 17 year old car with rusting rocker panels. I'm inclined to add a can of 134a and see what happens. If I can keep it going with a can every year, I'm good with that.
______________________________
 

HotZ28

Full Member
7,098
344
83
Buick Ownership
1996 Roadmaster Limited Collectors Edition 58k - 1996 PAU
If adding a can every year will keep you cool, that would be the best solution. Good luck, and keep us informed.
 

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
Just waiting to make a trip across the border... R134a is not available in Canada for the DIY, but you can purchase R12a. Unless I'm mistaken, R12a is hydrocarbon based and illegal to use in automotive AC, but not illegal to sell. Ultimate irony is Canada's attempt to protect the environment drives the DIY to mix refriderant (bad idea, illegal too?). As far as I know, I can purchase R134a in the US and bring it into Canada. Not many people can easily get to the US to do this. I should change jobs and get my AC lisence and start fixing people's AC. The trouble is I care too much about the work I do I'd be undercut and put out of business by those who don't care. I'll stick to my day job.

I'll let you know what happens after I get the 134a in.
 

jerreich

Full Member
213
2
18
central wi
Buick Ownership
2001 Buick Lesabre custom money pit
When I bought my 01 lesabre, the AC compressor made a bit of noise. The PO had an estimate for replacing the comp, orifice tube, accumulator, and recharge for $990.00. She decided to get a newer car. I put in 6 oz of PAG oil, 2 cans of R134A, and it worked all summer.; Last year, I put in 1 can of R134A, and it worked again all summer. Tried this year, and two weeks later compressor made more noise, then quit cooling. It is obvious that the orifice tube is now plugged. Ordered the comp kit from Rock Auto for $170.99, and will be flushing the whole system. So, for about $250, I should have a system that will last several more years. I do have all the tools to do this.
 

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
I added a can of this: http://www.oreillyauto.com/site/c/detail/INT0/AF22/N1783.oap?ck=Search_N1783_-1_2966&pt=N1783&ppt=C0050

It took the entire can, but now the A/C compressor runs. It's still on the low side.

I'm not sure I like the fact it contains a sealer, and there's no dye in the oil. Being that the A/C worked well last summer, and that it took a whole can of refrigerant, I'm guessing there's a bad leak somewhere. I've got a can of dye to put in, but it needs a different charge hose, one that pierces the can opening. Another trip to the US.
______________________________
 

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
I got a new charging hose and a 12oz can of R134A with UV dye. That brought the low pressure up to between 25 and 30psi (it was 18°C outside) which is just on the low side of good. What this does mean is that I didn't lose all the R134a I put in a couple of days ago.

I'll keep an eye out for leaks now.
 

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
For Canadian readers new to AC issues: Retailers don't sell R134a here, but will try to sell you R12a (not R12). Some may even try to tell you it's R134A! I don't know enough about AC to know if mi×ing R12a and R134a is a bad idea or not. However, I know I can't unmix it after myself, so I didn't chance it. Some one else can chime in on R12a.
 

Enslow

Full Member
603
4
0
Vancouver BC
Buick Ownership
1997 Buick LeSabre
Mixing refrigerants is illegal in Canada and the US and will not offer the maximum performance available from RED TEK® 12a.

http://www.redtek.ca/products_refr.html#
http://www.redtek.com/win_12a_refintro.html
I'm sure a lot of people in Canada are mixing it, all because Canadian law requires only those certified to work with R134a to use it. For that reason, you cannot buy 134 in Canada. I was encouraged to mix it by some one at a major store chain :eek:
______________________________
 

HotZ28

Full Member
7,098
344
83
Buick Ownership
1996 Roadmaster Limited Collectors Edition 58k - 1996 PAU
I was encouraged to mix it by some one at a major store chain
The Num-Nuts who sell refrigerant, should be required to have the same EPA 609-A certification that I was required to get to service A/C units. Bunch of idiots out there!
 

Johninmi

New member
3
0
1
Buick Ownership
03 Lesabre
For Canadian readers new to AC issues: Retailers don't sell R134a here, but will try to sell you R12a (not R12). Some may even try to tell you it's R134A! I don't know enough about AC to know if mi×ing R12a and R134a is a bad idea or not. However, I know I can't unmix it after myself, so I didn't chance it. Some one else can chime in on R12a.
one is high heat and the other is low heat mixing them defeats the purpose of using the other... If you are switching from r12 to R134A you have to completely evacuate the system pull the AC pump and replace the seals with a kit designed for 134A... Its not an easy process probably better to just find a place that still has r12 and have them charge it for you. The thing about r12 in the usa is we aren't allowed to make it anymore. If its still around it can be used up but we have completely made the transition to r134a in vehicles 1995 (and some 1994 vehicles so you really want to check your auto manual) and up... so most cars on the road will probably now days use 134A anyways.
 
Last edited:
Pedal Commander
Top