I have twin electric fans directly on the radiator, I have set the thermo switch to come on at 88 degrees c and it is independent of the ignition switch, should I connect the auxiliary fan directly to the thermo switch and disconnect the original wiring which put it on with the aircon or leave it independent or wire it to the thermo switch with a diode in the line.
your thought please

 

All the units I have done over the years have had the RH fan wired as a thermo only, using the factory 85c switch in the lower hose inlet to the water pump to switch the earth of said relay.

The LH is wired to the a/c circuit, and as long as a/c is switched on that fan runs. I did experiment, loooong ago, with a pressure switch for that fan, but they were way too unreliable for my liking. Maybe technology has caught up, dunno. Also remember, ALL mine have a compressor by-pass switch installed, so the climate system can be run without the a/c compressor running.

I kept it very simple, so reliability was achieved, and little gremlins kept out.

Nothing worse than 47c and the a/c dont work due to some resistor or diode having a hissy.

Both my V12's were 4c at the centre vent with this set up, and the ambient temp had little effect. The engine temp NEVER went anywhere near the "N" EVER.

 

Replacing the engine-driven fan entirely, I presume?




So far, so good







Do you mean literally connect to fans to the thermo switch?

Whatever scheme you settle on make sure your wiring and swiches can carry the amperage load of the e-fans.



You'll want some method of ensuring that there's airflow thru the condenser or the aircon won't work. If you still have the engine-driven fan that should do the trick.

Also bear in mind that (unless you've modified the circuit as Grant has) the aircon compressor operates in all climate control settings....even when heat is called for....so any fans connected to the compressor clutch circuit will be operating virtually all the time unless your select "off" on the climate control knob




Independant from what? And a diode in which line?

Sorry, I don't quite follow

Grant's set-up sounds good to me

Cheers
DD

 

RGP

I have Grant's setup on mine and it works brilliantly. Aircon fan on all the time the qircon is on, big electric fan controlled by the thermo switch in the pump inlet, activating the fan via a relay.

Several thousand hot miles since over the last two yeasr and really good performance. The only mod I have made is to put a timer module between the thermostatic switch and the relay. This means that once switched on, the big fan will run for 90 seconds even if the thermo switch cuts out.

Greg

 

I think I will go down that road to gregg