1997 golf fans not working
 

temp gauge reads normal, overheat light blinks (engine overheats) and fans do not come on.the fans run w/ac, i have replaced the rad fan switch, temp sending unit,water pump,and the brain box under the coolant res. i also removed the thermostat.
The plugs for the rad fan switch and brain were both corroded badly and have been replaced.
If i jump the rad fan switch the fans work..
What am i missing?????