Electric Cooling Fans

[Fless]

The switch is going to burn up, the fans draw about 40amps

He apparently has the relay setup, just needs to add control.

 

[JPVortex]

If you know which wire is the ground that needs to go to the PCM, that would be your relay ground to run through the switch.

Ok thanks, then I just need to ground the switch and I should be good?

 

[JPVortex]

The switch is going to burn up, the fans draw about 40amps

Didnt even think of that damn

 

[Fless]

Didnt even think of that damn

Doesn't matter if you're controlling the relay. It takes the current, not the switch. Think about it, could the ECM circuit handle that current? Nope. Hence the relays.

 

[JPVortex]

Doesn't matter if you're controlling the relay. It takes the current, not the switch. Think about it, could the ECM circuit handle that current? Nope. Hence the relays.

That's true, thanks for the lesson in electrical haha. I really know nothing about electrical lol.

 

[Scottydoggs]

you really need two relays, one for each fan, pretty sure i mentioned this in a earlier post. you can power both relays from one switch and with one split power supply lead to the relays.

 

[JPVortex]

you really need two relays, one for each fan, pretty sure i mentioned this in a earlier post. you can power both relays from one switch and with one split power supply lead to the relays.

The stock fan wiring has 3 relays, which is what I'm doing. All I'm doing is manually cutting or giving the circuit ground which is exactly what the PCM used to do at one point.

 

[JPVortex]

Figured out the correct spots for all the wires and theyre all wired up! They work great.

 

[ivin74]

Figured out the correct spots for all the wires and theyre all wired up! They work great.

You have pics?

 

[Rocket Man]

Figured out the correct spots for all the wires and theyre all wired up! They work great.

So this must mean you’re not getting a signal from the PCM to turn the fans on. I know you can buy a used one programmed to your VIN on eBay or similar so you could go that route since it looks like it’s not turned on in your tune. I wonder if the previous owner swapped in a used PCM from an earlier year that didn’t have that pin turned on.

 

[ironrickbob]

have you tested the fans? nevermind I see that now
have you checked fan harness? if there is voltage at the relay and the fans work with 12v applied then there has to be a break somewhere in between.

Hi there I've got the same problem only mine electric fans work when the AC is on .... new relays ... you said some thing about the temp sensor being 2 sided ...and if I unplug it , the fans should come on ...
Cross yo fingers ...

 

[Doubeleive]

Hi there I've got the same problem only mine electric fans work when the AC is on .... new relays ... you said some thing about the temp sensor being 2 sided ...and if I unplug it , the fans should come on ...
Cross yo fingers ...

wasn't me, must have been someone else. I remember someone mentioning the temp sensor at the engine block having 2 outputs (i think)

 

[Scottydoggs]

Hi there I've got the same problem only mine electric fans work when the AC is on .... new relays ... you said some thing about the temp sensor being 2 sided ...and if I unplug it , the fans should come on ...
Cross yo fingers ...

likely me said that......if the fans come on ect unplugged. all the wiring works as it should. sensor maybe bad.

 

[ironrickbob]

likely me said that......if the fans come on ect unplugged. all the wiring works as it should. sensor maybe bad.

I've unplugged the sensor , the fans came on ... replacing the sensor tomorrow...how gully it'll fix it

 

[ironrickbob]

I've unplugged the sensor , the fans came on ... replacing the sensor tomorrow...how gully it'll fix it

Put the new sensor in ..... nothing ... I'm at wits end .... so tired of this

 

[Rocket Man]

Put the new sensor in ..... nothing ... I'm at wits end .... so tired of this

What exactly is your problem? You said if you unplug the temp sensor the fans come on. Is your truck overheating or is the ac not working right or what? The temps that the fans are set to come on are in the tune. Stock is 190 I believe? And any time the ac compressor is on the fans are supposed to be on.

 

[Scottydoggs]

Put the new sensor in ..... nothing ... I'm at wits end .... so tired of this

how do the wires to the pig tail look? any cracks or bare wire showing? worst case you leave it unplugged and just have the fans on full time.

 

[Doubeleive]

did you check the fan harness plugs like I pictured?

 

[mattbta]

What exactly is your problem? You said if you unplug the temp sensor the fans come on. Is your truck overheating or is the ac not working right or what? The temps that the fans are set to come on are in the tune. Stock is 190 I believe? And any time the ac compressor is on the fans are supposed to be on.

Stock 05+ fan settings are quite high, so high that if the cooling system is in good shape, they might not turn on under normal driving and decent ambient temps with AC off.

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[Marky Dissod]

Factory '05+ fan settings are quite high, so high that if the cooling system is in good shape, they might not turn on under normal driving and decent ambient temps with AC off.

When I converted from one mech fan to two electrical fans, I implemented the following settings:
Fan1 ON @ 219F (OE, minus 7F)
Fan1 Off @ 212F (OE, minus 7F)
Fan1 ON Temp AC ON 284F ? how does this make any sense? does anyone know what this does?
Fan1 Enable AC pressure 215psi (OE, minus 5psi)
Fan1 Disable AC pressure 150 psi (OE, leave it alone)
Fan1 Enable Delay 0.30sec (OE, leave it alone)
Fan1 Disable Delay 0.20sec (OE, leave it alone)
Fan1 Minimum Time 75.0sec (OE, minus 15sec)

Fan2 ON @ 226F (OE, minus 9F)
Fan2 Off @ 218F (OE, minus 9F)
Fan2 Enable AC pressure 305psi (OE, minus 5psi)
Fan2 Disable AC pressure 230psi (OE, leave it alone)
Fan2 Enable Delay 0.20sec (OE, leave it alone)
Fan2 Disable Delay 0.30sec (OE, leave it alone)
Fan2 Minimum Time 195.0sec (OE, minus 15sec)