aux fan help needed.

[Unearth078]

using a Bosch 4 pin relay, i am trying to get the fan to kick on high, when the low temp thresh hold is hit on a e36 m42 rad switch. I have done all my testing by jumping the gn/bk and bk pins on the temperature switch.

I have given up for tonight due to finding out my switched 12v is staying on after the motor. the fan kicks on when turning off the motor.
If i find the correct switched 12v should i be in business?

Thanks
Mike

[DaveSmed]

Pin 86 is incorrect. Make it a ground. Or, if you <3 DIN standards/have a relay with a built in diode, do that and swap 85 and 86, making 85 the ground and 86 from C113

[StereoInstaller1]

Lotta grief for nothing.

Wire the damn Spal with the stock wires, swap low and high on the radiator switch (leaving the stock low unused) and you are done.

[Unearth078]

Pin 86 is incorrect. Make it a ground. Or, if you <3 DIN standards/have a relay with a built in diode, do that and swap 85 and 86, making 85 the ground and 86 from C113

i see i over analyzed this. thanks man! with a second set of eyes it all makes sense.