heating/cooling issue

[mikeonb4c]

Using the ac button doesn't keep the fans on though does it? only puts then on when compressor loads up I think.

I often wonder why the a/c does make the fans come on. Is it because the engine will be working harder, so might as well ensure a guarantee of good cooling even when stationary (classically where aircon might be used in hot humid Jap traffic jams where no air is going to be naturally flowing over the rad)? The point then is that even if the rad fans do come on, will switching the aircon on just cause the engine to generate more heat, thus negating the point of doing so.

Despite understanding the logic of the argument against it, I still feel that turning heaters on may help. However it is done, the job is to disperse excess heat. At worst, all that should happen is heaters on causes the main rad. to reduce its involvement in overall cooling by roughly that amount the heater rads are taking care off. At best, if the main rad./circuit is compromised through blockage of some sort, then heater rads may bring a net improvement. I don't know I'm right about this, but I wonder. It would be useful to get some test data from someone with a TM2 type temp sensor fitted.

[missfixit70]

The rad fans come on for the ac to cool the ac condenser in front of the rad.
The heaters do remove a small amount of heat up to a certain point, BUT my argument is that without realistic temperature monitoring, you don't know where it's working & where it isn't if that makes sense. With an unmodified temp gauge & an undiagnosed coolant problem, it's a big risk IMO.
With a modified temp gauge/Mason alarm or other temp monitoring such as TM2/Ialert/cube or any other temp gauge fitted in a position that gives a realistic idea of temperatures, then you stand a chance of not causing more issues as you'll be able to see any fluctuations that will not be visible with an unmodified gauge, but even then it's a fine balancing act.

[mikeonb4c]

The rad fans come on for the ac to cool the ac condenser in front of the rad.
The heaters do remove a small amount of heat up to a certain point, BUT my argument is that without realistic temperature monitoring, you don't know where it's working & where it isn't if that makes sense. With an unmodified temp gauge & an undiagnosed coolant problem, it's a big risk IMO.
With a modified temp gauge/Mason alarm or other temp monitoring such as TM2/Ialert/cube or any other temp gauge fitted in a position that gives a realistic idea of temperatures, then you stand a chance of not causing more issues as you'll be able to see any fluctuations that will not be visible with an unmodified gauge, but even then it's a fine balancing act.

Yes, that all makes good sense.

And switching on aircon to get rad fans working doesn't seem a sensible idea if what is wanted is more cooling, without causing engine to generate more heat (OK, even the back EMF in the alternator when rad fans are running will cause some extra load on the engine, but not of the same order).