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Carnut
09-29-2011, 12:20 PM
Earlier this year, the air conditioning on my 99 Lightning was no longer cooling like it should. I have never had issues with it before.

So, I popped the hood, checked for leaks, compressor operation and all the standard stuff. Since the Lightning is 12 years old with 125,000 miles on and since I had never had the a/c service, I suspected that enough refrigerant had leaked out over the years it was no longer up to snuff.

Not wanting to spend money at the shop, I went to O'Reilly's and bought a rechanrge kit, which was a couple pounds of R-134 with charge oil and a quick connect hose with a guage.

I had a heck of time finding the suction charge port. The high side port was easily found but not the suction side. I spent hours looking for it, trying to trace the line etc. Finally, I took the plastic cover off the electrical junction box next to the battery on the firewall but it was still not visable. In frustration, I followed the line back to the firewall with my hand and found it. It is buried under the box and there is no way you can see it.

So, I took the protective cap off the charge port, pushed on the quick connect fitting and started the truck and turned on the ac. You should use protective gloves and glasses so refrigerant does not get on your hands or in your eyes. You can insta-freeze whatever comes in contact with escaping refrigerant.

On the can, it lists the maximum charge pressure in relation to the outside air temperature. YOU NEED TO NOT EXCEED THESE VALUES.
In my case it was 55 pounds, so I slowly filled it, watching the guage, until I got up to nearly 55 pounds (psi). I let it run a little while to allow the pressure to stabilize then removed the disconnect.

I shut of the motor and let it cool, then reinstalled the cap. The reason I let it cool, is I could not get the cap on without using my bare hand (no sense of touch with a glove) and did not want to burn myself.

I restarted the motor, turned on the ac and put a temperature guage in the vent. It was blowing 60 degree air with and outside air temperature of 110 degrees. It was working fine.

It has been several months since I did the recharge, still working fine so I guess I had no major leaks.

So, instead of a couple hundred bucks at the dealership, I spent thirty bucks on the recharge kit. The hours spent finding the right port was the only PITA.

Gr8snkbite
09-29-2011, 12:31 PM
Nice job nut boy....tho I'm surprised the seals didn't fail on you....not having used it in so long. The refrigerant actually acts as a lubricant for them...

VaporDude
09-29-2011, 02:56 PM
I need to work on the 94 Mustang A/C. I put R-134A in it and the compressor still won't come on. I think there is a ECC unit by the overflow that may need to be replaced.

Carnut
09-29-2011, 03:04 PM
I need to work on the 94 Mustang A/C. I put R-134A in it and the compressor still won't come on. I think there is a ECC unit by the overflow that may need to be replaced.

You might want to see if you have power to the compressor clutch first, then if not, troubleshoot the electrical supply side. Might be as simple as a power fuse for the compressor or the ECC unit as you suspect. Just a thought.

I am a little curious how you got refrigerant in it without the compressor working. Some systems have under/over pressure switch that won't allow the compressor to be energized. Not sure about your specific car.

VaporDude
09-29-2011, 03:15 PM
You might want to see if you have power to the compressor clutch first, then if not, troubleshoot the electrical supply side. Might be as simple as a power fuse for the compressor or the ECC unit as you suspect. Just a thought.

I am a little curious how you got refrigerant in it without the compressor working. Some systems have under/over pressure switch that won't allow the compressor to be energized. Not sure about your specific car.

You can put in only so much but it doesn't mean it circulated through the compressor. I am betting only the lines themselves have that much pressure. I looked back at some of my threads on a local Mustang site and they suggested to change the CCRM (Constant Control Relay Module). It controls several components such as the A/C compressor clutch, fuel pump, high/low/cooling fan. I heard that they do go out regularly. I just ordered one off E-Bay for $50 shipped. I'll see if that takes care of the problem.

Carnut
09-29-2011, 04:35 PM
Hope it works for you.

VaporDude
09-29-2011, 07:12 PM
Me too......