Auxilliary pusher fan

[Don-T]

Has anyone installed an auxiliary pusher fan on a 3rd gen truck? There is not much room between the bumper / grill and the A/C condenser.

 

[rbattelle]

Do you have that much of a cooling problem? Or just over-engineering?

 

[Don-T]

I am thinking about the fan to help keep the trans cool when maneuvering the camper. At crawl speeds the trans can get hot because of lack of air flow. I think the A/C might cool better at idle too with more air crossing the condenser.

 

[sag2]

The Napa low line slim line just fits. The premium Napa fan is a little too deep. Don't have the part number, but they should be able to find it for you. Wire it in to the A/C clutch with a relay.

 

[Matt400]

Originally posted by Don-T

I am thinking about the fan to help keep the trans cool when maneuvering the camper. At crawl speeds the trans can get hot because of lack of air flow.

Better yet how about a switch on the dash that will turn on your factory Vistronic Fan?



The factory fan will pull way more air than a pusher can do.

Running the OE fan for slow maneuvering, backing and such is a great idea IMO especially for automatic trans trucks.

Sure... you can turn on the A/C and get the fan powered up but then you are also pulling super heated air off the condenser and through the rest of the heat exchangers.



I have been developing/testing a circuit just specific to this application and will finish up soon. It has been interesting to do as the ECM can pick up on any irregularities going on with the fan so some ECM fooling is involved.

In my latest testing I ran the fan continuous for 10 minutes with no check engine lamp and am now doing testing to verify its usefulness in cool-down times.



I live at the top of a grade and once I exit the highway I flip the switch for the 5 minutes it takes to the driveway.

I would think while exiting a freeway for a fuel stop flipping the switch would be beneficial for cool-down/shut-down time.



I have been working on this for several months now and wasn't going to say anything till I was finished but since you asked maybe its time to feel others out for the interest.

 

[rbattelle]

Matt,



WOW! I anxiously await more info on your project!



How are you "fooling" the ECM? Does your circuit mask it's activity to the ECM so the computer isn't aware what the fan is really doing when the circuit is on?

 

[Matt400]

Originally posted by rbattelle

Matt,



WOW! I anxiously await more info on your project!



How are you "fooling" the ECM? Does your circuit mask it's activity to the ECM so the computer isn't aware what the fan is really doing when the circuit is on?

Actually I tried that route in the beginning and it didn't work, the fan operated but the ECM recognized the operation when there was no command for it and set a code & lamp.



My final approach is the best IMO by having the ECM start and monitor fan engagement it won't set a code.

The final control switch will be a nice brushed aluminum toggle with a red illuminated led in the tip to remind you the ckt is energized just in-case you can't hear the roar of that BIG FAN!

 

[rbattelle]

I want one!

 

[Matt400]

Ok... its been a part time project so far but I will speed things a little more now.



Tracking down the right vendors for high quality components yet keeping the costs down has been taking time too with phone tag and changes to the final product.



I will shoot for July 1 for the first kits available, posting that here will give me a deadline.

 

[Blakers]

Originally posted by Don-T

I am thinking about the fan to help keep the trans cool when maneuvering the camper. At crawl speeds the trans can get hot because of lack of air flow. I think the A/C might cool better at idle too with more air crossing the condenser.

As far as cooling the transmission, unless I'm outdated, these engines have a water-cooled transmission cooler on them in series with the air-cooled transmisson cooler. At idle the engine temp is so low, it should keep your transmission well cooled.



I believe your A/C will turn on your big fan at idle and provide plenty of air for cooling the A/C condenser.



Blake

 

[Don-T]

The transmission heat is a problem when backing up a heavy trailer. The engine fan may not be running, the engine temp is warm enough to not cool the trans fluid enough and there is not enough air through the trans cooler to help. At times like this the torque converter is really heating up the fluid. I think an extra fan would be a big help.

 

[Matt400]

I was surprised to find that the factory did not include programming allowing the OE trans thermistor to communicate slow speed or reverse maneuvers to the ECM.



In the beginning I was testing a fully automatic method that used the transmissions OE thermistor to communicate with the ECM and turn on the fan but realized I may want the fan to come on at one temp while someone else may want it sooner/later.



I did find that if you work the engine hard enough while backing the ECM will turn on the fan for engine temps thus cooling the trans also but relying totally on that won't work for slow pace low throttle settings.

 

[David Oxland]

I've wanted to be able to do this for braking on long hills: I had a "Horton" that I could force operation on and it was great for long hills . When the engine is turning fast it consumes quit a bit of power giving a worthwhile braking effort.

 

[Matt400]

Thats an interesting approach... haden't thought of using it that way. I am sure you would have to have geared down and have RPM's up for any noticeable help in braking.

 

[rbattelle]

Call me a "control freak", but the more items I can have control over in the cab the better.

 

[AndyMan]

Any word on electronically controlling the Fan?



Also, has anyone replaced the crappy plastic fan with a nice aluminum flex-a-lite or something?

 

[Matt400]

Oh thats not a crappy fan, it will pull way more air than any aftermarket is capable of. I developed a ckt to control fan engagement for slow off road use, traffic and long backing situations. PM me if you want details.

 

[jelag]

I have to add 2 cents here... I have an 04 that's stock... . I pull a trailer that weighs between 18 and 22K most of the time... (trailer weight) and have pulled the grapevine and the Sisikyou's (6%) and across the desert from San Diego to Phoenix at over 100* with no overheat problems... . it works fine..... why add to something that works...



Jim

 

[rbattelle]

it works fine..... why add to something that works...



Jim

Oh, sure, it works "fine". But it can always work "better". If it ain't broke, fix it 'til it is!

 

[Matt400]

why add to something that works...

Your right it does work great on the road but there are times when backing a heavy trailer... not into a regular camp spot but say off road for 100 yards cuz there is no turn around at the end the whole time no air flow over the cooler cuz the engine is cool enough. Times like that its nice to flip the switch. Also for me I live at the top of a grade and when I pull the boat home most of the time the fan is not engaged because the engine is cool enough, turbo is pretty darn hot though and requires idle time which I do with the fan engaged for cooler intake air.