@geraldkrug

I made something similar.
Hiddeing switch to ignite radiator fans manualy ;)
Automaticly they start at 90°C now I can do thath at any time before engine become too hot.

@Cowman
That's hard to do and harder to bring to market. I had a faulty automobile cooling fan on a Chevrolet Cavalier and I just kept it running constantly. I bypassed the fan heat sensor.

@geraldkrug

Exactly what I do.
Bypass thermo sensor with couple wires and two switches to manualy start 1 or 2 fans.
Old diesel deserve good cooling before transform self in turbo sauna:)