4WD and AirCon

On a Jimny when 4WD is engaged the Aircon is disabled by design. I've been trying to figure out the logic behind why this is complication is necessary. Anyone have any ideas.

Thanks

Probably a combination of saving a bit of power to cope with the rough terrain, and stopping the electric fan running.

I recall getting involved a while back in sorting out a couple of them that didn't work.

From memory, the aircon switch is 2 pole. One turns the light on all the time the other operates the air con, but the air con clutch only gets an earth when the 4wd controller is in 2wd mode.
Easy enough to bypass the 4wd controller IIRC.

But why would you 'need' to do this given that the aircon has a perfectly good user controlled on/off switch. The power used by the aircon is marginal as is any possible extra power requirement when in 4WD.

I'm pretty sure my 2001 jimny aircon stays on when in 4wd.. i remember thinking how nice it was green laning and staying cool rather then getting slapped round the face by branches with the windows open.
I cant clarify that atm though as I'm sure someone has recently stolen all my refrigerant

It works in mine

But i do have a rocklobster box & manual hubs in a push-button jimny, so the 4x4 module isnt connected anymore, therefore no signal to make it stop (or any dash lights, which is on the job list).

Riccy wrote: It works in mine

But i do have a rocklobster box & manual hubs in a push-button jimny, so the 4x4 module isnt connected anymore, therefore no signal to make it stop (or any dash lights, which is on the job list).

Here is an off the wall thought. Off-roading may make the cooling system work harder and so does aircon. Both together - is it too much for the vehicle.

But as an opposite thought, the cooling fan is running continually with the air con on, so the engine is actually cooler?

rappey wrote: But as an opposite thought, the cooling fan is running continually with the air con on, so the engine is actually cooler?

Good point though isn't it just one rad coping with all of this?

helijohn wrote: Good point though isn't it just one rad coping with all of this?

No, on for engine coolant, one for refrigerant. You can't mix the 2.

It runs cooler, as rappey says the electric fan is forcing air into both rads. Ive actually put it on specifically to cool the engine a bit on hot days. Does make it easier to stall at low revs however.

Busta wrote:

helijohn wrote: Good point though isn't it just one rad coping with all of this?

No, on for engine coolant, one for refrigerant. You can't mix the 2.

Ooops silly me I had a "moment".

With the aircon on it could be said that its like a cooling system with an electric fan .
The AC fan runs continually blowing air through the condenser AND the engine cooling system radiator.
My jimny running temp never fluctuates whether I'm hammering it, stationary in the traffic from hell or driving at an easy 40 mph, aircon on or off make no difference to my engine temp so couldn't say about AC and offroading..
One stupidly hot summer a few years back in my car I was stuck in yet another traffic jam from hell on a motorway. Quite a few cars boiled over..
My engine temp climbed above the norm a fair bit and I was so hot, so threw caution to the wind, wound up the windows and put the AC on.
My car is a similar setup as the jimny with the condenser in front of the rad and the car uses the engines electric cooling fan when the AC is on.
bugger me, the engine temp dropped dramatically when the AC was turned on !
So that's a Mercedes and a jimny that both cool down with AC running!
Strange though as when driving through death valley a while back there are plenty of signs warning not to run the AC as it may cause the engine to seriously overheat !
When offroading the viscous fan is spinning, the engine may be in low range so would have thought that is a lot less stress than driving at 70+ on the motorway (on the autobahn of course )
Interesting discussion though !