Whenever I start the car the fan that sends cool air into the car does not come on. Sometimes whenever you hit a bump or give the dashboard a sturdy hit then it comes on. I have heard that it can be a multitude of things like a bad fan switch, a blower motor, and even a relay. I don't know what it is and I was wanting to know what it is. I NEED A/C!!

The fans should run whenever the AC is on. But if it's off, the fan should only run when the computer thinks the temp is too high

Is your radiator fan working the way it should? If car cools down with forward motion it seems that the forward movement is doing the cooling and when you stop there is no cooling.

I would need to hear the noise to diagnose the possible cause.

They are right. It is difficult to find a bad or loose connection When the compressor is not cooling, open the hood and start moving the ac wires. You might be able to find it yourself.

your electric fan for the AC is not working for whatever reason so when idles its all getting hot the engine and the AC system .This sort of work can be difficult to diagnose correctly and a code reader is about as good as a bible at mosque so seek the advice of a skilled mechanic who should be able to pin point the fault in seconds

the cooloing fan comes on also whenever the a/c clutch engages, as well as when the temp hits about 200 degrees F

girlfriends honda had the same problem, all it was was a lose connection on the blower motor. i thought it was the blower going bad but i took the dash out and put it all back together and it fixed the problem. hope this helps.

think the front panel is pushing on the switch ,you will need to have a good look

The O/D off means your overdrive is off. Have you accidently bumped it? It could be the start of a problem with electrical system. Usually a bad ground on your O/D may cause this. Intermitten problems are the hardest to track down and fix. Do you know what overdrive does? It's a gas savings device which cuts the engine's RPM's down by something like 1/3, like a 5th gear. That's why you are experiencing the jerking on the highway. Do you have an owners manual? If not a good place to look for one is at a local salvage yard, or online even. There may be something in there to explain this to you a little better than I did. I had a frien who had a simular problem. It turned out to be a bad fuse. It wasn't blown, it was broken, and it's element would jiggle around when he would hit bumps in the road. I don't know if this helped you, but it will give you place to start looking.

Yes this car should have a temperature sending unit that tells the fans to kick on. If it has two fans one of them is for you Air-condiontion, and it will turn on whenever the ac is being ran. One other possibility is if you bought the audi used the owner before you may have hard wired the fan to run whenever the car ignition is turned on. The only reason someone would do that is if they were to lazy to fix it properly.