Bongo Fury

I'm not positive that my rad fans are working as they should - I'm going to check the first speed setting with the A/C on and sensor unplugged - thanks Graeme I will probably change the water temp sensor but in the meantime...

I'd like to fit a switch to put the rad fans on when I see the head temp rise and when I am labouring slowly up some of the more challenging hills round here - or stuck not moving in holiday traffic.

I don't want it to replace or over-ride the sensor (if it is working) but would like the chance to help the cooling system when needed. I'm sure I've heard the second stage fans come on but that was not until the engine was sudenly stationary at the top of a longish climb.

I know Mike has done the scavanger switch - but could anyone tell me if this is possible and how you might do it?

Lights blue touch paper and stands well back.

The logic I used was v simple. The existing supply was left undisturbed. A completely new (alternative) feed was provided, direct from the battery but via a switch and fuse. A realy would have been better practice for this but I had a switch, fuse, wiring set from some 100W spotlamps etc. that seemed adequate (and the fuse would tell me if not!).

I imagine that if you try this trick with the rads, and unless you can suss out if there are separate feeds for stage 1 and stage 2 rpm, then using my trick is likely to put the fans on at the higher speed. But that would be my preference anyway, cos if you want them on at all, you want them on good and effective. Once they've done their job (the mason etc. temp gauge will tell you if/when they have) you switch the manual override switch (doncha just love this Thunderbird 2 / James Bond / Mercury space capsule stuff ) off.

Personally, I'd go for it. Mind you, there is a strong case for saying that the system as designed should do what you are proposing to do using manual over-ride. But then again, who's to say the sensors are doing their job reliably on an old Bongo?

Mike - where did you get the switch from and where did you mount it? Your main live just from the battery or did you tap a switched live?

Doublepost - just seen your supply from the battery. Do you think you could connect the live from the sensor end? Or would it be better to access the junction boxes to the rads underneath the bonnet and behind the radiator?