There are after market switches that bypass all that, and you run them when you need them.
They are not difficult to install. I hear the electric water pumps work wonders too.

 

So after you replace the dual temp sensor and that doesn`t help,it must be the computer,I am I right?.I have had to ground the no.1 cooling fan relay and both fans will run low,good for now.I would rather have it working properly.

 

Does anyone know where to get these aftermarket parts to by bass the computer`s control of fans?. Thanks,Mark

 

If the fans run at low speed and do not run at high speed, take a look at FAN relay #1, the windings probably went open.