Palm’s bible references disabling the auxiliary fan bootstrap circuit to aid with post-shutdown cooling, and provides the following directions.




What does he mean when he says connect “it” to a 12V power supply? Am I supposed connect the LG wire to the 12V power or do I connect the 12V power to terminal 4?

 

I think the Great Palm is advocating hot-wiring the aux fan circuit so that the fan will always run, ignition on or not, if the aux fan coolant temp switch in the water pump inlet spout is closed, ie if the water is above 85 degrees C.
Myself, I would not so this as it would be all too easy on a hot day to return to a flat battery.
I always pop the bonnet when I stop after a hot run, even in a public car park just releasing the catch and not actually fully opening the bonnet makes a difference to under bonnet temps. It is not the water temp on shutdown that matters, it is the heat under the bonnet cooking the wiring that is the problem.
I did some proper measurements a few years ago,
bonnet closed: under bonnet air temp was still over 80 degrees C after two hours;
bonnet open, air temps after 5 mins were down below 50
bonnet released but on the safety catch, under 60 in 30 mins.

 

I bypassed my fan switch and wired in a tasteful toggle for on off, helpful in stop n go city traffic. I've thought about wiring in line a 10 minute shutdown timer but it's hardly a priority.

If your onto this task, and say if I had to do it again I'd re-arrange the fan to run ON - 10min - OFF but I didn't splurge for the three option toggle haha. It does help but I've forgotten the fan was on and came back to a dead battery morecthan once.

 

That’s an interesting idea. I always fully open the bonnet when I return home, but have wondered about what to do in a public car park — especially one where the tarmac is baking under the summer sun. I’ll have to give that a try.