Radiator Fans Troubleshooting

[Mr Brown]

The Bentley links are all broken. Does anyone have a troubleshooting/test procedure for the fans?

I have an early EV with AAF engine and want to confirm the fan speeds. I think they are three speed fans.

With a/c on, will they always run at speed 2?

With ignition on(not running) I get what I believe is speed 1 on the fans. On a hot day, as soon as I start the van with a/c on, the fans go to a higher speed which I believe is speed 2. On cooler mornings with a/c on, the fan runs at a low speed.

Does this sound right? Also want to confirm I am getting speed 2 and not 3.

[BatesEV]

https://just-t4s.co.uk/downloads/ac%20heater.pdf

Look down at high pressure switch. It says when pressure gets above 232psi fans go to speed 2

[dazey77]

There are 3 speeds (for the radiator (engine) fan). Two are triggered by the 3-pin temp sensor on the radiator (its on the left as you stand peering in). Get a wire loop, take the connector off and bridge pins. When you find the ground you should be able to bridge ground to A and get one speed, ground to B and get another speed.
Speed 3 is the OMG speed and is triggered by another circuit and over different wiring (thankfully as I burnt my wiring for speeds 1&2 when my AC compressor clutch went). Speed 3 kicks in with temp guage at about 3/4 (which if 1&2 are working you shouldn't hit), normally temp guage is middle ish.
With AC on, fans always run, I thought it was speed 1 but I could be wrong.

With ignition on you shouldn't have any engine fans running unless its hot. You are possibly confusing engine fan and the internal blower fan? The blower will run with ignition on.
_________________
My van modification blog:
www.dazedproductions.co.uk/Vanity

[Mr Brown]

Thanks for the replies. I will jump the rad sensor to confirm.

I believe it is working correctly as when it is cooler and I run the A/C the fan runs on low(1) and if hotter it runs higher, thinking that is speed 2.

It is odd that the radiator vanes are fully closed at startup during ambient temperatures that would require A/C. The condenser must get pretty hot until the vanes open which explains the higher fan speed which controlled by the pressure switch; higher system pressure when hot . Seems like the fan runs for no reason until vanes open.

[dazey77]

The vanes are another thing.
They are meant to mechanically open when hot but they are a common faliure point.
I (like many) have the contol device removed and run with them cable tied open. I sometimes shut them in winter.
_________________
My van modification blog:
www.dazedproductions.co.uk/Vanity

[Mr Brown]

Confirmed I am getting two speeds from radiator fan switch so all good I guess.