4.0l XJ overheating? Start here - the basics!

[werd]

I would think the trans temp would be best but 4wd indicator easiest.
What say you?

[junglejuice]

Originally Posted by werd

I would think the trans temp would be best but 4wd indicator easiest.
What say you?

I looked at the diagrams for the 4wd indicators and gave up, I just use the manual switch when I select 4wd, but don't forget if you're running the AC the fans will change to high automatically as well...

[werd]

If you found the wires for the 4wd switch, I wonder if a transistor instead of a relay for the trigger might be better. Less current draw?

[junglejuice]

I didn't look into too much, just looked at the diagram but the switch for the high-range and low-range is a rather "unusual" arrangement, so yes maybe a transistor connected to the lamp feed will do the trick, if you work it out post the circuit...

[werd]

Before I start this project could you answer two questions please?
#1 You have said if you're running the AC, the fans they will change to high automatically. Does that mean they run at low speed as well?
#2 When the fans cut in at 106°, isn't that a bit late to start cooling? With the stock setup the belt fan is already trying to cool the system down before the electric fan cuts in.

[junglejuice]

Originally Posted by werd

Before I start this project could you answer two questions please?
#1 You have said if you're running the AC, the fans they will change to high automatically. Does that mean they run at low speed as well?
#2 When the fans cut in at 106°, isn't that a bit late to start cooling? With the stock setup the belt fan is already trying to cool the system down before the electric fan cuts in.

Ok, the way it works is like this, in auto the fans both run in low speed mode so you're getting airflow across the entire radiator just at a lower speed, once the AC or the temp rises to the point that the aux fan would normally turn on the fans both change from low to high speed.

When in manual mode the fans both run at full or high speed irrespective of the temp or the AC status.

If you use the trans temp or 4wd input the result is the same as manual.

Does this help clear things up for you?

[werd]

Sure does, thanks. I don't think I've ever seen the electric fan move until it hit 106.