Electric Fans - Pin 33
May 2, 2009 | 08:06 AM
#71
Staging Lane
Joined: Sep 2005
Posts: 51
Likes: 4
From: Davie, FL
Update, a request was put in to Hp Tunners for air recirculation door control.
Bill said "I've already put in the request"
So maybe the Hp guys will have this option as well soon.
Bill said "I've already put in the request"
So maybe the Hp guys will have this option as well soon.
Last edited by apex2112; May 2, 2009 at 08:15 AM.
May 10, 2009 | 03:27 PM
#72
I am pretty sure the 03 and 04 are the same. I did it on my 04....
Here is the thread.
https://www.performancetrucks.net/fo...ighlight=efans
Hopefully your using EFI Live, cause HPtuners does not have the AC pressure adjust needed to control the second fan correctly....
http://www.hptuners.com/forum/showthread.php?t=8858
Here is the thread.
https://www.performancetrucks.net/fo...ighlight=efans
Hopefully your using EFI Live, cause HPtuners does not have the AC pressure adjust needed to control the second fan correctly....
http://www.hptuners.com/forum/showthread.php?t=8858
not sure if its been said but you can do the fans and a/c with hpt now. you have to request the beta.
May 10, 2009 | 06:51 PM
#73
The diagram that Nonnie posted up, along with others, appear to be the diagrams for the Nelson type wire harness which uses the (+) tap (green wire) of the AC clutch to activate the second fan. They've been somewhat modified... and in the case of that one the verbiage for the A/C clutch was not removed but the line schematic shows going to a switch contact and to ground. Trace it and it goes to the coil of a relay which has positive voltage on the other side of it. It confused me also when I first looked at it and read the verbiage, hence me telling Nonnie that it wouldn't work because the A/C clutch is a positive voltage. That lead should say PIN 33 of the PCM which provides a ground to complete the circuit and close the relay.
Again anyone reading this..... it is really simple. If you want to use 2 pin controlled e-fans 99-2007 use the attached schematic to wire up a harness and have your PCM tuned to use both pins 42 and 33 of the PCM.
EDIT:
Here is a description of their operation.
Cooling Fan Control - Two Fan System
The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the powertrain control module (PCM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the underhood fuse block.
During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the low speed fan relay coil, closes the relay contacts, and supplies battery positive voltage from the low fan fuse through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan s/p relay and the right cooling fan. The result is a series circuit with both fans running at low speed.
During high speed operation the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. After a 3 second delay, the PCM supplies a ground path for the high speed fan relay and the cooling fan s/p relay through the high speed cooling fan relay control circuit. This energizes the cooling fan s/p relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the high speed fan relay coil is energized closing the relay contacts and provides battery positive voltage from the high fan fuse on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.
Important
The right and left cooling fan connectors are interchangeable. When servicing the fans be sure that the connectors are plugged into the correct fan.
The PCM commands the low speed cooling fans ON under the following conditions:
* Engine coolant temperature exceeds approximately 94.5°C (202°F).
* A/C refrigerant pressure exceeds 1447 kPa (210 psi).
* After the vehicle is shut OFF if the engine coolant temperature at key-off is greater than 101°C (214°F) the low speed fans will run for a minimum of 60 seconds After 60 seconds, if the coolant temperature drops below 101°C (214°F) the fans will shut OFF. The fans will automatically shut OFF after 3 min. regardless of coolant temperature.
The PCM commands the high speed fans ON under the following conditions:
* Engine coolant temperature exceeds approximately 104.25°C (220°F).
* A/C refrigerant pressure exceeds approximately 1824 kPa (265 psi).
* When certain DTCs set.
At idle and very low vehicle speeds the cooling fans are only allowed to increase in speed if required. This insures idle stability by preventing the fans from cycling between high and low speed.
Again anyone reading this..... it is really simple. If you want to use 2 pin controlled e-fans 99-2007 use the attached schematic to wire up a harness and have your PCM tuned to use both pins 42 and 33 of the PCM.
EDIT:
Here is a description of their operation.
Cooling Fan Control - Two Fan System
The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the powertrain control module (PCM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the underhood fuse block.
During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the low speed fan relay coil, closes the relay contacts, and supplies battery positive voltage from the low fan fuse through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan s/p relay and the right cooling fan. The result is a series circuit with both fans running at low speed.
During high speed operation the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. After a 3 second delay, the PCM supplies a ground path for the high speed fan relay and the cooling fan s/p relay through the high speed cooling fan relay control circuit. This energizes the cooling fan s/p relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the high speed fan relay coil is energized closing the relay contacts and provides battery positive voltage from the high fan fuse on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.
Important
The right and left cooling fan connectors are interchangeable. When servicing the fans be sure that the connectors are plugged into the correct fan.
The PCM commands the low speed cooling fans ON under the following conditions:
* Engine coolant temperature exceeds approximately 94.5°C (202°F).
* A/C refrigerant pressure exceeds 1447 kPa (210 psi).
* After the vehicle is shut OFF if the engine coolant temperature at key-off is greater than 101°C (214°F) the low speed fans will run for a minimum of 60 seconds After 60 seconds, if the coolant temperature drops below 101°C (214°F) the fans will shut OFF. The fans will automatically shut OFF after 3 min. regardless of coolant temperature.
The PCM commands the high speed fans ON under the following conditions:
* Engine coolant temperature exceeds approximately 104.25°C (220°F).
* A/C refrigerant pressure exceeds approximately 1824 kPa (265 psi).
* When certain DTCs set.
At idle and very low vehicle speeds the cooling fans are only allowed to increase in speed if required. This insures idle stability by preventing the fans from cycling between high and low speed.
All the settings are setup in the tune of course..
But highlighted in red, ive never had mine do that. I had it set low and it only ran for the requested amount of time i setup in the tune. Never had it run until the ECT was below the set limit.
Just thought bout it, and ive forgot about this thread.
May 10, 2009 | 06:54 PM
#74
If you look under the Fuse box there is a stud on the front side of the truck that gets power straight from the battery. Its the Main Power Wire for the Fans. So atleast a 30A fuse.
Jun 6, 2009 | 05:10 PM
#75
Assuming the nelson harness is like the one White1 made for me way back when. Then you need to hook the connector for the AC wire to an ignition switched power source and connect the ground wires (which is probably slot 85 from the schematic above) on Relay's 2 and 3 to pin 33. To make sure it wasn't wired backwards test for continuity between the AC switch wires and slot 55 and 56 on the relay connector. The one of those two that doesn't have continuity is the ground.
Last edited by truckmann; Jun 6, 2009 at 05:15 PM.
Jan 31, 2010 | 11:19 AM
#76
How do I change this text
iTrader: (26)
Joined: Jan 2005
Posts: 7,294
Likes: 2
From: Behind the TIG welder
Well I just went to install my 05 fans and harness in my 03 2500. and Pin 33 is not working to control the fan. Is there any 03 guys that got this to work using HPTuners?
Jan 31, 2010 | 12:58 PM
#79
