cooling fan not working

I just bought a 94 jetta III gl and I got it up to running temp. and the fan never switched on. Also my heater or a/c fan does not work what should I do????

While idling did you let it get to the top of the temp scale? Did it overheat and the temp light startedflashing? Are you in reference to the blower fan inside the vehicle? Does it work in any of the speed positions?

No, it made it to about 3/4 of the way up and I shut it off.

Yes, the blower fan does not work in any setting.
Could this be the resistor????

I had the same problem, and believe me, it sucked!!! This is what I did to solve the problem. First I looked to see if the cooling fan fuse had blown... no surprise there cause it did. Next I tried putting in a new fuse and after getting it up to normal running temperature the new fuse blew as well. I figured that there must be a problem right at the fan motor so I investigated. Everything appeared to be fine, but when I felt the electrical connector on the fan motor (the white plastic thing that's stuck to the top of it with wires comming out), the connector just kinda jiggled around and felt like it was loose. When I spun the fan blades by hand, the connector kind of jiggles around which each spin of the fan. I decided to take the fan assembly with its support bracket out of the car. This is the tough part because there really is no easy way of getting it out. I had to disconnect the AC hose that was on top of the radiator in order to make room to pull out the fan (be careful with this AC hose because it is reverse threaded). Unfortunately this discharges your entire AC system, but whatever, you might as well clean it out and recharge it with the $30 kits you can buy almost anywhere. After the AC hose is disconnected, you can tug and tug and eventually pull the fan out. Once I had the fan out, I took apart the motor assembly and realized that the insides of it had turned to crap! I tried to re-wire it myself considering the cost of a new fan, but trust me... it is hopeless. What you have to do is go out and purchase a new fan motor. Sometimes you can find them cheap on ebay or elsewhere. Once you put the new fan motor on its housing, just work the fan back into the car and bolt it back down. Then you may want to re-charge your AC. Hope this helps!

Motors are common to fail, there's also fuses in the dash & on the control module on the left shock tower. There is also a thermal switch on the radiator. 3/4 of the way up is often not enough to trigger the fan to come on. If ther interior fan will not come on in any position I'd go to the motor & run 12V straight to it to see if it will run.