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cmitch
Expert
Date registered: Apr 2006
Location: Ala-Tenn
Vehicle(s): 2002 ML320, 2005 S430 4Matic, 2010 F150 Super Crew
Posts: 3412
| Air Conditioner not working?
Today, I found out the AC on the 99 ML isn't working. I swapped relays and checked fuse 44. No dice. The compressor does not kick in nor does the aux. fans work. I have some possibilities.
1. The aux. fan(s) could be bad, but unlikely, causing the compressor not to kick in when the AC button is pushed.
2. The compressor could be low on charge/ bad causing the Aux. Fans not to work.
Anyone have any additional thoughts and possibilities as to what could be the problem? |
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DUTCH
Administrator Doppelgänger
Date registered: Apr 2006
Location: US, GA, Atlanta
Vehicle(s): 2015 Audi Q7 3.0 TDI,2018 Sprinter
Posts: 9963
| RE: Air Conditioner not working?
cmitch - 3/20/2008 8:36 PM
Today, I found out the AC on the 99 ML isn't working. I swapped relays and checked fuse 44. No dice. The compressor does not kick in nor does the aux. fans work. I have some possibilities.
1. The aux. fan(s) could be bad, but unlikely, causing the compressor not to kick in when the AC button is pushed.
2. The compressor could be low on charge/ bad causing the Aux. Fans not to work.
Anyone have any additional thoughts and possibilities as to what could be the problem?
How's your R-134 charge? If it's too low, the low pressure safety switch will prevent operation. |
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cmitch
Expert
Date registered: Apr 2006
Location: Ala-Tenn
Vehicle(s): 2002 ML320, 2005 S430 4Matic, 2010 F150 Super Crew
Posts: 3412
| RE: Air Conditioner not working?
I took it to my indie today and he put his recovery unit on it. It showed 1 lb of charge (holds 1.7 lbs.) He recovered the freon, pulled a vacuum, recharged it- no go. He then pulled a vacuum again and then tried to turn the compressor- seized up! So, I guess it's A/C system time. Geez.
Edited by cmitch 3/22/2008 9:10 AM
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cmitch
Expert
Date registered: Apr 2006
Location: Ala-Tenn
Vehicle(s): 2002 ML320, 2005 S430 4Matic, 2010 F150 Super Crew
Posts: 3412
| RE: Air Conditioner not working?
OEM Compressor-$485.00 Drier Accumulater- $55.00 Labor- $150.00 to $200.00 The ability to hang meat in the back of your car: Priceless |
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Noodles
Date registered: Dec 1899
Location:
Vehicle(s):
| Re: Air Conditioner not working?
Hi Mitch, sorry about your A/C problem. Glad you got it fixed.
I have diagnosed a small leak. I do have access to recharge equipment. So I charged it with 134a.
Added the PAG oil per the WIS and the leak dye. It lasted about 10 days. Now the system is down
to 8psi.
I will break out the UV light and glasses to find where the freon went. I am hoping it is not the condenser.
Hopefully just an o-ring or a hose.
The compressor is spinning fine.
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cmitch
Expert
Date registered: Apr 2006
Location: Ala-Tenn
Vehicle(s): 2002 ML320, 2005 S430 4Matic, 2010 F150 Super Crew
Posts: 3412
| Re: Air Conditioner not working?
Noodles - 6/21/2008 4:34 PM Hi Mitch, sorry about your A/C problem. Glad you got it fixed. I have diagnosed a small leak. I do have access to recharge equipment. So I charged it with 134a. Added the PAG oil per the WIS and the leak dye. It lasted about 10 days. Now the system is down to 8psi. I will break out the UV light and glasses to find where the freon went. I am hoping it is not the condenser. Hopefully just an o-ring or a hose. The compressor is spinning fine. It's most likely an o-ring. But it could be something more serious, as well. Ditto that you hope it's not the condenser. That would be expensive. Now, I'm having a 'new' problem. The air is blowing 65º, instead of 54-56º, like it should. It's the devil to get the car cooled down on a hot day. Charge is fine. It makes me think that the expansion valve is malfunctioning. The gauges should tell the story and I'll get it checked out later this month. Right now, I'm going to concentrate my resources on finding the mysterious roar in the left rear wheel of the ML320. I hope that it isn't the wheel bearings. |
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Noodles
Date registered: Dec 1899
Location:
Vehicle(s):
| Re: Air Conditioner not working?
Good news, the dye was all over the fitting for the low side hose at the condenser end. Got a new o-ring and
tightened it up. Added the PAG oil and charged it up. So far it is holding.
Yup the gauges will tell the story, if there is an incorrect difference between the high and low side then something is blocked.
I hope the evaporator did not eat up tiny bits of compressor. That can lead to warmer air blowing even with a good charge.
We had that grinding noise and it was the darn inside rotor e-brake shoes stuck due to a rusty adjuster. I hope yours is
that simple.
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Noodles
Date registered: Dec 1899
Location:
Vehicle(s):
| RE: Air Conditioner not working?
Well well well........
It started blowing hot air with a good charge. So I looked around. The condenser was slowly dying. The biggest issue was the air blend door motor. Followed Detane's thread at BW and saved huge money.
The dealer wanted 1800.00 for the condenser, and $1200.00 for the air blend motor replacement. Got the condenser for $150.00 the motor for $130.00 and once I had the condenser out I did not like the look of the receiver/dryer so I got one at the dealer for $119.00.
I did need a mechanic for 2.5 hours, but all said it was $600.00 instead of $3000.00 or more at the dealer. It was blowing 38º F out the center vents when I was done with it and is holding up well now. |
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