efan problem

[bottomline2000]

I have the new PCM in and they still cycled low. I removed a relay and it sounded like something was loose inside. I tapped on it and the fans cut off, but did not cycle back on based on engine temp. the one fan did come on when I turned on the a/c though. I replaced the relay with a new one and even swapped them around and they still will not cycle on and off. They stay on low until I turn on the a/c then cycle to high. pcm doesn't seem to know what the engine temp is so it defaults to keeping them on. no CEL or anything. weird...

 

[bottomline2000]

anyone got any ideas on what may be causing my fan problem? I think the fans both cycled to high today. before it sounded like they were both going high with the a/c, but I think it may have only been the one fan for the a/c. I let it sit running in 100 deg heat today and all of a sudden I get a big amp draw and the fans really sucked a lot of heat out the radiator and someone standing next to my truck backed up since it was blowing so hard. my temp gauge dropped so it seems they are trying to work. still won't turn off completely.

luckily its hot as hell in TX right now and the constant running of the fans is not a problem. I'm getting 15mpg even with the a/c blowing so the truck is running good.

Jenna, the PCM should be there in the next couple of days. if you got any suggestions let me know.

 

[Justin]

anyone got any ideas on what may be causing my fan problem? I think the fans both cycled to high today. before it sounded like they were both going high with the a/c, but I think it may have only been the one fan for the a/c. I let it sit running in 100 deg heat today and all of a sudden I get a big amp draw and the fans really sucked a lot of heat out the radiator and someone standing next to my truck backed up since it was blowing so hard. my temp gauge dropped so it seems they are trying to work. still won't turn off completely.

luckily its hot as hell in TX right now and the constant running of the fans is not a problem. I'm getting 15mpg even with the a/c blowing so the truck is running good.

Jenna, the PCM should be there in the next couple of days. if you got any suggestions let me know.

You should be able to determine if just one fan or both are running by looking at them with the engine running. Standing beside the driver's side fender with the hood popped should give you enough of a vantage point to see.

Justin

 

[bottomline2000]

yeah, I'm sure they are both running. Today was the first time I noticed the amp draw and the fans pulling a lot more air so they both must have cycled to high. maybe my thermostat is jacked up and its stuck in open loop.

 

[bottomline2000]

regardless of this small problem with the fans I could not be happier to have them today.. 107 in Dallas and my truck was loving life!! Damn it was nice to drive around without the roar of that clutch fan and feeling of pulling a large parachute and worrying about overheating all while freezing my butt off lol...

blackbear tune had me plowing through traffic in comfort. Thanks for all the help on this Justin..

 

[bottomline2000]

efans won't turn off!!

I'm bumping this back up since I still have the same problem. My blackbear harness was starting to melt at the relay so I decided to go ahead and get another one. I still have the constant on of both fans. I went with a Nelson harness this time and be damned if nothing has changed. I run my power wire directly to the battery from the alternator bypassing the junction box, but the fans get their power from the junction box by way of the pos wire from the battery to the junction box I seem to be the only one having this problem. Could this be causing my problem? I'm sure other people are bypassing the box.

I've done this install so many times its ridiculous. I would like to move on to getting my suspension work done, but this is irritating the hell out of me. any ideas would be greatly appreciated.

 

[Rivieraracing]

Are you sure you are using the correct A/C wire, the green one? There were 3 wires in the truck harness that looked like they would be the right color but all 3 had different characteristics to what they did to the fans! One didn't let the fans come on at all, one had the fans come on all the time no matter what, and the last one I found and tried that actually looked to be the correct one color wise made them work correctly!!

 

[bottomline2000]

Yeah I actually went thru the same thing when I first installed the harness. I'm sure I have the right wire tapped and I even traced the wire back to the compressor. I can disconnect the a/c tap and the fans do the same thing, both cycle low. I turn the a
a/c on and they cycle high. I'm going to a wire from the alt to the junction box and see if this fixes the problem. Justin from blackbear even sent me a new PCM to remove some potential problems and I still have this issue. I only have one spot open around pin 42 so I couldn't tap the wrong pin if I wanted. I don't have any check engine codes or anything so the only thing left is the power supply.

 

[JennaBear]

Gianni, shoot Justin an email, maybe we can change your operating system.

 

[bottomline2000]

Wow, thanks Jenna. Will do. I just changed the thermostat, changed the belts and flushed the coolant all for the sake of these fans so a few things to rule out. Riviera I want to say I did my wire tap based on some pics you posted now that i think about it.