what is the point in the fan blowing and cooling the coolant more, if the coolant isn't flowing due to the thermostat blocking it?

-mcnaught6 you don't seem to understand, it's not so much the engine or even coolant temp in the block we are trying to control. The point is to keep the fan on a little longer/sooner to help keep the auto tranny a little cooler. The cooler sits out in front of or in the radiator so bringing the fan on longer/sooner may benefit tranny fluid temps, especially since there are already problems keeping the tranny cool and alive when wheeling in warm weather on long slow inclines.

Think about it :thinking: , if you pump cooler water (which it will be due to the fan running over the fins of the radiator) into a warm engine it will be cooler then if the coolant was just sitting there. You in essence will be pumping cooler water into the engine when the mechanical thermostat opens up.

If you look at a JK radiator on an auto transmission vehicle, you'll notice that the engine water radiator is behind the A/C condenser coils, the bottom 4" or so (edit: of the condenser coils) includes the automatic transmission cooler (already built in). In fact, there is very little of the engine water radiator that's directly exposed to the grill air. That's the extent of my knowledge on the vehicle layout.

The question we are asking is by lowering the temperature turn-on point of the fan (which is controlled by the temperature of the engine), will there be any benefit for the A/C and automatic transmission? I would hope that there would be significant cooling benefits, especially for the transmission. I would think there would be little effect on the engine cooling since it is controlled by its own thermostat. The fan normally comes on to keep the engine from getting too hot, not necessarily to keep the transmission cool.

Now that the details and hypotheticals are on the table, I hope Hypertech can confirm.

while it is possible there may be some benefit for the tranny (although i doubt it, because when you reprogram the computer, i would assume it is still reading (and hence controlling the fan) by the temperature of the engine block).....if you pump "cooler" coolant to the block, the temp of the block would drop faster than normal, causing the thermostat to shut off sooner than normal, but still at the same exact temp.

i.e. even if you program the fan to run 10 degrees lower than normal, then engine would never actually reach that lower temp, because the thermostat will never allow the engine temp to get that low. so the problem might be that the fan would run all the time since it would be trying to cool the engine this lower temp, that it cannot reach, because the fan can't make the engine that cool all by itself, without the coolant flowing through the thermostat.

maybe i'm completely wrong, (and as it was pointed out, just don't understand) but this is my speculation.

i'll shut up now, since i'm probably just wrong.

It DOESN'T MATTER what the thermostat does. All we are really worried about it moving air across the A/C-TRANNY-RADIATOR assembly primarily the A/C-TRANNY cooler wich is in front of the radiator. This would help to cool down the tranny fluid to prolong it's life. The thermostat is going to open/close normally and yes the engine may get a little colder water but not enough to really make a difference. I don't think it will make a major difference in the tranny temps either but any bit will help. The thermostat that open/closes to allow flow isn't a directly coupled unit to the fan. The fan has it's own sensor to tell it to turn on/off, yes usually associated with the flow of warm water across the fans temp sensor when the thermostat opens. If we can set the fans on-temp limit lower and keep air flowing across the tranny cooler longer/sooner we should see some benifits to tranny fluid temps.

I think we have all made good points but I now see what you are saying MCNAUGHT6. In fact I think the only people this will benifit are the ones with an AUTO. Manuals dont need or have trans coolers. SO, I think it would benifit the automatic guys.

An auto guy will have to do a writeup with a temp sensor to confirm unfortuantly when I get my update I will only be able to comment on the standard trans performance.

Still waiting on the update for my programmer. :crazyeyes:

Darnell, does the next round of updates include calibration for 05187284AE?

UPDATE JUST BECAME AVAILABLE. I was notified by email.

Here is my update.

https://www.jk-forum.com/forums/atta...1&d=1204657689

I still have not recieved any email. Darnell could you please check why I have not recieved any email.

Is my calibration still not updated