A/C just decided to quit working.

Post by **OrangeAirsoft** » 08 Jan 2006, 01:22

the A/C blows air, but no cold air at all. tried recharging, the 134a doesn't seem to leave the can.

car is 86 740 turbo

thanks!

Kmaniac in California USA · Post by **Kmaniac in California USA** » 08 Jan 2006, 07:08

I have a couple questions for you regarding your A/C.

First of all, the 1986 Volvos came with A/C systems that use R-12 refrigerant. Has your system been converted to R-134a? If not, I wouldn't suggest mixing the two types of refrigerant.

Next, do you have pressure gauges to measure the pressures on both the high and low sides of the system while it is operating? I wouldn't try to add any refrigerant unless I know the internal pressures. Besides, the measured pressures will tell you instantly whether or not the system is fully charged.

Now for the strangest question of all, can you still change the direction of output air flow between the defroster vents, dashboard vents and under dash vents using the dashboard slide control? Likewise, will the heater still blast out very hot air when your temperatue control is slide all the way to the right? This is an important thing to check. Your vent and temperature controls are activated using engine manifold vacuum. There is a vacuum reservoir tank under the front end of your car, which is positioned in front of the front crossmember between the front tires. The precarious position of this tank makes it an easy victim of damage from running over road debris. If this reservoir has been damaged and no longer holds vacuum, your vents will default to the defroster mode and no air will blow from the dashboard vents. Likewise, the temperature control valve will not open and you will no longer be able to heat the interior of the car on a cold day. A vacuum leak such as this can also effect the turbo boost in turbo equipped cars. Take a look at this before you go any farther.

Keep us posted as to what you find. I like to hear success stories.

AMcK · Post by **AMcK** » 08 Jan 2006, 10:31

Were you using an r-134a connector on an r-12 service port? see if the compressor is coming on, if it dosent then hoook some gauges on and you can see if it's electrical or low on refrigerant, if it's low on refrigerant then you have a leak and it will need to be fixed, then the system will need to be put into a vacuum and charged, you'll probably wanna have a profesional do it since you need some special equipment. Retrofitting the system to r-134a will probably be the best way to go since r-12 is so expensive now.