Cooling fan runs too much and it never reaches operating temperature

Cooling fan starts running when car is started and will never reach operating temperature and will not shut down until car is turned off. I replaced the sending unit at rear of engine, since that is usually what it commonly is. Oh yeah, the temperature gauge only comes up like two to three lines, guessing maybe 100 degrees and goes no further. Took relays out one at a time under dash. Pulled one out at a time and started car to see if it shut the fan off. Did a total of four under there. First two I know were the right ones and seen two more with same numbers, so did them as well. So I figured last thing I am knowing about is thermocouple on radiator, pulled plug off, restarted car and the fan was running. So Ia m kind of at a loss on ideas and VW usually can be salty in price, so I am not playing hit or miss. Thanks, mark