I noticed the oil temperature got quite high when I was stuck in traffic – it sat at 92C, wich would be fine when moving as the pressure would build up, but when it’s idling the pressure is only 1 bar. The size of the cooler make no difference when stuck in traffic and going nowhere.
So I decided to look at using the external alarm on the SPA gauge to drive a relay to drive some fans mounted behind the oil cooler.
I used 2 x 5″ server fans, one was 1A, the other 0.9A. They shift a reasonable amount of air, so we will see if it is enough.
The relay was one I found on some old wiring loom, it switched at 105 Ohm. The max load on the outputs for the gauge is 100mA, so a couple of resistors were used. The pins are correct for my relay, so don’t go by the numbers, match up the relay diagram to your pins.