I have no mechanical fan in my 240, most vehicles built now-days don't.

I used the lower hose pipe from a 740 with the switch in it, controlled the relay by putting power to #30 and #86 with the key ON, grounded #85 thru the switch, and #87 to power the fan which is seperately grounded. All this is fused thru a 20A circuit breaker, and 30A fuse.

I wanted to install an A/C pressure switch, but needed to change the drier to get the required "extra" port, which I have not done. I just do not run the A/C when trapped in traffic. All you would do is to install another switch, ground one side, and the other would go to #85 with the wire for the other grounding switch in the lower hose pipe.

Now, one may ask "why the LOWER pipe?" Simple, what is the good of turning on the fan IF the radiator is able to keep the outlet water colder than Tstat opening -20*F? None. As long as the inlet water is colder than the stat FULL OPEN temp -20*F, you DO NOT need the fan. As an alternate thing, you could use the stat full open temp plus a few degrees and signal from the upper radiator hose, head, or water outlet. As long as the thermostat is NOT "full open", you do not need maximum cooling (fan on). Hotter engines produce lower emissions and better economy.
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JohnG 1989 245 MT @ 235,000