car a/c

[murray75]

Firstly,

I work on cascade systems in my day to day job, so I am familiar with refrigeration fault-finding and repair.

Ok. The compressor in my car started to make a rumbling noise, but still worked for a while after that. Now the comp doesn't even come on any more so I am thinking it needs replacing. I was shocked when the guy at the local garage said he would recover all the gas, vac it out and recharge it then see if it worked! Is that the best he can do for fault finding? So that means I'll pay for recovery of gas when I don't think it has leaked, then pay again for new gas only to be told they have to recover it again and have a think about what to do next.
I would have thought car a/c repairers have a fault finding procedure, rather than just recharging gas. Anyone know of reputable national auto a/c companies?

[Brian_UK]

Anyone know of reputable national auto a/c companies?I think that is known as an oxymoron.

Some places just do a re-gas whilst others could fit a new system if required.

Depending on the age of your car compressor controls are pretty basic - on/off switch, low pressure switch or a superheat switch with a high pressure switch for the condenser fan.

Electrical check is based around -
Circuit fuse.
On/off switch putting out power.
Compressor clutch, pulling in, power to clutch?

[Karl Hofmann]

Sadly the newer cars are a little more complicated, many use clutchless compressors with a solenoid valve built in to direct the refrigerant flow, either in a loop in the compressor or off to the expansion, this is usually controled by a module which controls the pulsing of the solenoid, cooling fans, blend flaps etc.... Car manufacturers love to take nice simple things and then overcomplicate them so that most folk prefer to take the vehicle to the main agent where their highly trained knuckle draggers have you at their mercy.. If the compressor was noisy then first find any leaks in the system, replace the compressor, lube, drier and if possible, expansion... Flush the pipes and other components, recharge and off you go. The refrigeration side is simple compared to what you are used to, the controls can be dumb.

As for finding someone who can do a decent job on your car, well a few years ago motor factors were pushing refrigerant management stations to every garage in the land promising vast riches for aircon recharges.... I think that you can figure out the rest.

[charlie patt]

need to know what make the car is if it has a noisy comp the likely suspects are citroen and audi/vw group unless you have a scroll on a saab let us know we can make more help as above says if gas low the damage is alredy done gas gets low to much heat in pump and fr clutch bearing goes.