AnyBody see this before?

ok. So I ordered a new fan control unit for my 98 foreman, put it on, same problem. Put on an oil temp sensor, same problem, oil light does not come on momentarily, so put old fan control unit back on and everything works
So I send back the fan control unit because it seems to be defective. They send me another new unit and I figure I will keep it for a spare.
I get the new unit and install it to check it, it does the same thing as the first unit I was sent! The shipper and I have double checked every number on my ATV and it should be the correct part, but when I try it my oil light will not come on like it does with my original part??
Any ideas on what could be happening?
Thanks in advance.