Flex-a-llite

[CumminsBu]

Anyone runnig a Flex-a-lite fan? I hate the plastic fan on this trucks.

 

[Matt400]

Taking it off will be a chore in ECM fooling to prevent a check engine lamp as the ECM controls and monitors fan engagement.



Its really an awesome set up in that it only pulls air as needed and the monster fan can if needed pull way more air than any aftermarket add on.

 

[Rineholio]

I have to agree with Matt400. Stock is the way to go on this one. I can't even remember how many big block cars started boiling over in the summer after installing flex type fans over the clutched stocker back in the early 70s when I was a hotrodding teenager. I also think the clutched fans use less power except for when you need them.



Jeff

 

[John - K5AWO]

Originally posted by Matt400

Taking it off will be a chore in ECM fooling, to prevent a check engine lamp as the ECM controls and monitors fan engagement.



Its really an awesome set up in that it only pulls air as needed and the monster fan can if needed pull way more air than any aftermarket add on.

Okay, so why isn't it pulling a LOT of air at idle when the OAT is 117 like it is today??



Took the lil darlin' out to get a snack, at every stop light, the dash air went up to 80*, I had to put the transmission in neutral and jump the RPMs up to 1000-1100 to get the air temp below 60*.



At 35-40, even in OD, it will discharge 40* air (after the duct work cools down again).



Either the ECM signal is not getting to the fan clutch, or mine has lost the capability to pull the load needed at low RPMs.



Never had a check engine light come on since I owned the truck.

 

[Matt400]

Originally posted by John - K5AWO

Okay, so why isn't it pulling a LOT of air at idle when the OAT is 117 like it is today??

Are you referring to an 03 or the 98. 5 in your sig?

 

[R.M.THOMPSON]

I'll tell you what I've done to a couple of vehicles as an "air conditioning bomb" , Install a aftermarket pusher fan with a t-stat connected to the hot gas line going in to the top of the condenser... . Set the stat for somewhere between 80 & 90 to start. This will allow supplemental cooling when a) the compressor is on, b) whenever it is over that air temp coming thru the grill. IMO using the clutch signal is annoying to say the least as in defrost mode in the cooler times of the year it will cycle way to much !!! I am in the HVAC trade and wander why your high pressure switch is not signallling the pcm to bring on the factory fan. . or could it be that you are low on charge due to a leak and can't develop enough refrigerant circulation at idle to do the job ? Our systems have a high pressure and a low pressure switch. Here's a quick check,when this condition occurrs , lift the hood and observe the what the compressor's clutch is doing. Hopefully it is note cycling on & off in that high of an outside temp.

Mark T.

 

[Don-T]

R. M. THOMPSON



I am not getting cold air at idle in my truck (04). I have opened the hood and at idle with the A/C on the fan is runninng slow and the A/C clutch is cycling on and off every few seconds. What does it mean?

 

[RonsRig]

Don_T, you need your AC serviced. You are probably low on freon and the longer you wait, the worse it gets. You might have a leak somewhere.

 

[Don-T]

The truck is going to the dealer in the morning to get the A/C checked. I hope they don't complain too much about modifications I made to the truck.

 

[Matt400]

Don-T,

It's true that if the refrigerant is low you can have that symptom however it is also possible that if your Vistronic Fan is not cooling the condenser then the high pressure switch will cycle off the compressor.



My truck did the same as yours and this TSB fixed it and allowed the fan to come on at idle to cool the condenser. I see yours is an 04 but wanted to point out high pressures will also cause the cycling.

 

[R.M.THOMPSON]

The dealer will figure it out as soon as the tech puts a set of gauges on it. In my pevious remarks I did'nt mean to remove the factory fan , if anyone was wandering ? This extra fan mod works wonders in traffic for colder discharge air temps and lower auto trans temps too. Good luck tomorrow and I hope they don't hit your refrig. circuit with DYE either. Thats kinda cheating if it can't be found with a leak detector !!!!!!!!!!!!!!!!!!!!!!! Matt400 hit the nail on the head... ... ...

Mark T.

 

[Prairie Dog]

This has been talked about before and it's normal for the third gens to cycle on for only 8 seconds or so unless the doors are open and your in very high humidity. My system was completely evacuated and recharged for a plenum door fix and it still operated exactly the same - and just like the other trucks on the lot. Also, my fan doesn't make much noise at idle but sometimes roars for a couple of seconds when I first take of from a stop sign. It runs a little longer when it gets hotter. I was in 104 temps and heard the fan run much more often than when it's in the 90s. The elect clutch always seems to disengage when you get above about 1500 rpms or so.

 

[Don-T]

I decided not to go to the dealer today. Last night the A/C worked fine so I don't think it is the charge too low. Last night the cooling fan was coming on at idle and the A/C compressor was staying on as it should. I talked to TST and they said it is possible their box is causing this because of a ground problem. My code reader shows no codes but when I cycle the ignition the odometer shows a P0480. I think that is a cooling fan code.