efan problem

[bottomline2000]

actually my problem is my truck doesn't seem to know when to activate the fans. They run constantly. Not with just ignition, I made that mistake. Once I start the truck both fans run on constant low. When the a/c is turned on they both cycle to high. I have flushed the coolant twice, replaced the thermostat, the coolant temp sensor, moved the a/c wire tap to a different section of wire, tried multiple computers, replaced the wiring harness nothing seems to fix the problem!!

I've had electricians look at it and the computer is grounding the fans and since its not factory no one seems to know how to diagnos the problem.

It sucks cause initially I only wanted the tune for the fans so ironically I love the tune, but the fans don't work right. The only thing left is to buy another set of fans.

I have no clue and this little upgrade has cost me a pretty penny and is really the only reason I don't want to dump any more $$ into the truck.

 

[waxworkz]

are you using the factory fans? i used the factory fans off an 05 tahoe. sorry i havent read all the details of your set up. i see in your signature, it says oem fans? but oem from what vehicle??

 

[bottomline2000]

I have fans from an 05 Yukon with nelson harness.

 

[waxworkz]

is your air conditioning system working ok? only thing that i can see causing that is a bad ecm or a short somewhere.

 

[Rivieraracing]

Sounds like you may want to think about ditching the nelson harness and go for a Black Bear one, I'd email Jennabear on here and ask their opinion on the matter!!

 

[bottomline2000]

I started out with a blackbear harness. That's why I have a Nelson one now.

 

[bottomline2000]

is your air conditioning system working ok? only thing that i can see causing that is a bad ecm or a short somewhere.

It has to be a short somewhere. A/c works fine, but there is something up with my fans. They seem to have a big amp draw. I currently have my stock alt with the blackbear pulley on and I can overload the system if I turn the a/c on high and the fans engage. There is a big drop in my voltage gauge everytime the fans cycle to high. My stock alt is 130 amps.

I blew my big alt racing my truck one night. Didn't like the rpm lol.

I have about 1400 rms in stereo and it's just too much for the stock alt to handle even with the pully so I don't even try to crank it.

All this leads me back to where I started. I want to start with testing the fans amp load. This will be the last time I buy anything electrical from a junkyard!

I've searched all over the Internet and only found one guy on pt net that had the same problem and it turned out to be tune related fixed with a patch but he was using something other than efi live.

 

[Rivieraracing]

Dang, sounds like you've been through your share of problems for sure with the e-fans!! There are a few folks on here from Texas, maybe one of them would be nice enough to chime in and let you try out their e-fans in your truck to rule out your fans as being the problem!! I would for sure if you lived closer to Oregon, let me know if you wanna drive up my way!!

Cmon Texas, can someone help a brotha out on this one!!

---------- Post added at 06:30 AM ---------- Previous post was at 06:26 AM ----------

Also, have you tried to run the fans with the green A/C wire DISCONNECTED to see if the fans work any different? Just an idea!

Also, for comparison reasons for ya, my fans will kick on and off with the A/C off and the selector knob on the defrost and defrost/floor mode and not kick on at all with the vent, vent/floor, and floor mode selected!

 

[bottomline2000]

Riviera I really appreciate the offer. Its all good. I will find the problem eventually. I don't want to pass a problem on to anyone else lol.

I have tried running the fans without the a/c tap and the same thing happens, fans run on low. The problem has to be in a wire shorting somewhere. Just don't know where and how. I'm going to check my ground wires. I did have my trans replaced last year, but that was before the fans. who knows something may be disconnected.

based on your a/c tap mine works fine. I can do the same and the only way I know mine cycles the same is both fans go to high like yours probably only cycles the one to high, difference is when the compressor turns off my fans cycle to low regardless of engine temp. If they would just turn off I would be good as I'm sure the computer will turn them on at the right temp.

I need to figure out what is causing the computer to ground the relay to activate the fans.

 

[sparg93]

the Blue42 pin, can someone explain to me how to tap this into the computer? Any photos available? (i've never messed with a computer before)