temperature gauge behaves erratically ?????

when i turn on the A/C after few minutes of driving,it drops down to a quarter and then it goes back to middle and so on
again it only does it when the A/C is turned ON

i replaced the Temp Sensor(parts from audi)

I had the thermostat, water pump etc. replaced,[:@](could it cause the problem if the parts are not from audi)

Thanks

 

What you need to do is make sure what the gauge is telling you is actually true, so you can either feel the hoses going into and from the thermostat and see if they feel the same, cool or hot.
Or the best route to go is find someone with a temp gun and measure the heat of the hoses.

 

WELL isn't the audi temp gauge always supposed to be in the middle

 

Yes im trying to show you how to diagnose the problem, you need to find out if its the gauge malfunctioning or the thermostat closing or opening, catch my drift?

 

i feel the drift, and i'm drifting but it seems 2 much work, i went to the dealership and they dont know what it is

 

LOL, ok what do you wan't me to tell you? You gotta do something, just feel the damn hoses when the gauge is fluxuating and see if the temp of the hose is getting hot and cold as well, i don't know what else to tell you.

 

where is the location of the temp sensor on an A4 2003?



thx