Need some ac help

So my system is charged and has great pressure with no leaks. The problem i am having is that my ac button will not come on or light up.there is no click to the button either. i replaced the fan control module and nothing.i was thinking it could be the fans but then again maybe the heater control unit is bad also. any advice from anyone that has experience is greatly appreciated.

The fuses, pressure switch, ac clutch. I could unplug the fans and supply 12 V to them to check the individual fans.

“Would”

i am going to try to put 12v to the fans today and see what happens. are there any relays under the dash i should look at or check? i have looked at every fuse and every one of them is good. thank you for your input Dieselmonkey02.

If the light isn't coming on the switch is probably bad. Of course the fan has to be on also. Its also possible fuse 25 is blown but that would cause the interior fan to not run as well.

You can verify if the switch is bad easily backprobing pin 8 (blue/red) at the fan control module and it should have 12v when the switch is pressed. If it doesn't then as a test jump 12v to your backprobe and see if the AC comes on.

I have seen the light not work due to switch failure at least 2 times. I think when I pulled the AC panel out the connector was a little burned up on those.

CoolAirVw said:

If the light isn't coming on the switch is probably bad............................

Click to expand...

/Interweb guessing that's right on the mark. Would imagine that switch must activate to get the little train rolling, fans, etc.

First and foremost thank all of you for your help. so there is this little hole above my a/c button. i decided to stick a poker in the hole to see if it were like a reset of sort. well the ac light clicked on and so did the fans. but i have to shut turn it on and off by this little hole. anyone ever seen this before? but any ways i have 13.4 volts going to the compressor and the compressor is now not turning on. i know the system has a charge to it or pressure in it anyways but i dont know if it is high or low but the compressor has 12 volts going to it. should it kick on???

What hole? Post a pic.

The on dash Fan position switch (Off-1-2-3-4) provides current to the AC Push Button switch in any position but Off. Once On and AC button is pushed in (ON), the current goes to the Fan Control Module (and ECU) to set in motion a sequence of events that turns on the AC system (Fans out front & AC clutch). There must be a minimum refrigerant charge or the fans will not function nor will the AC clutch kick-on (talking AC function only).

The left Green 30 amp fuse in the panel on the battery, the middle 40 amp strip fuse in that panel and Fuse 16 in the fuse panel on the left of the dash are all part of the mix.

The temp sensor switch on the rad is wired somewhat separately and can be bad (non-functional) and have zero affect on AC function.

I've been through all of this with my 2000 Jetta over the last few days as well as several others recently!