06_KingRanch
SDD Junior Member
I have a 2006 King Ranch with the upfitter switches and im wanting to wire the fourth switch to be a high idle switch. I found this review on ebay and i was wondering if any of you guys have wired them using the single wire like he did. I realy dont want to burn anything up so if anyone has some knowledge about wiring it with just a single wire let me know.
While many Super Duty owners enjoy their trucks for their towing capacity and their creature comforts, most Super Duty trucks are built for work. The engine management computer program that is resident in Super Duty trucks with power-take-off transmissions (PTO) is also a part of the computer program in EVERY Super Duty. A simple matter of applying 12 volts to a circuit, along with setting the parking brake and having the transmission in Neutral or Park, will bump the idle speed to 1200 RPM. Changing any of these states reverts the truck’s engine to normal idle until all of the parameters are again met.
What does a high idle accomplish? Among other things, should you need to have your truck idle for an extended length of time, high idle reduces the possibility the engine “wet stacking” or developing excess carbon deposits on the injectors. In colder weather, it can reduce warm up time. In warmer weather, increased coolant flow and airflow across the radiator due to the increased engine fan speed can reduce the chance of overheating at idle. It can speed battery charging. High idle can maintain passenger compartment heating and cooling. But what was Ford’s purpose for designing this feature into the engine management system?
Here’s one example. Super Duty trucks are used in vehicle wrecker fleets. In order to drive the hydraulic pump that makes the tow dolly move up and down to lift a stricken vehicle, the engine speed on the Super Duty needs to be increased. An operator could put a foot on the accelerator, put a stick on the accelerator, or flip a switch and let the truck’s computer do the work. Or another. The utility bucket trucks that have a lineman repairing electric lines from a hydraulic lift arm. The hydraulic pump is driven by the truck’s engine.
There are many other reasons that you may think of for using this modification, which simply uses Ford’s own engine computer management to control your diesel’s idle speed. This modification comes from data compiled from Ford Motor Company files, and should in no way compromise the warranty on any vehicle.
How to make the high idle circuit
Use an upfitter switch, because that is one of the uses Ford designed them for. As the amperage required for control of the PTO function is very low, use AUX 4, a 10-amp circuit.
As you remember, the blunt cut wires for the upfitter switches are at the rear of the fuse panel. Select the Orange/Light Blue wire, which is controlled by the AUX 4 switch and relay. Behind the parking brake, look for another bundle of blunt cut wires. Ford calls this the Customer Access or CASC bundle (the bundle is there so the trucks can be modified by Ford approved body manufacturers). There will be 11 individual blunt cut wires, including four pass-through wires for the upfitter switch circuits. You are looking for one, a purple/light green wire. As there is not enough wire to reach from the fuse panel to the CASC bundle, you will have to make a small jumper cable. Four to eight inches, depending upon your finger dexterity, should be long enough.
Connect the Orange/Light Blue blunt cut wire from the upfitter switch wiring harness to the Purple/Light Green wire in the CASC bundle, using butt connectors and the jumper cable.
In order for the high idle to work, the engine management system must sense the following states:
Parking brake set
Transmission in Park or Neutral
Service brake not engaged
Press the parking brake, place the transmission in Park or Neutral, and then start the engine as normal. To test the circuit, bring the AUX 4 switch up. The idle speed of the engine should increase to 1200 to 1250 – RPM, even rising to as high as 2400 – RPM depending upon the state of battery charge. Release the parking brake. The idle speed should return to normal.
While many Super Duty owners enjoy their trucks for their towing capacity and their creature comforts, most Super Duty trucks are built for work. The engine management computer program that is resident in Super Duty trucks with power-take-off transmissions (PTO) is also a part of the computer program in EVERY Super Duty. A simple matter of applying 12 volts to a circuit, along with setting the parking brake and having the transmission in Neutral or Park, will bump the idle speed to 1200 RPM. Changing any of these states reverts the truck’s engine to normal idle until all of the parameters are again met.
What does a high idle accomplish? Among other things, should you need to have your truck idle for an extended length of time, high idle reduces the possibility the engine “wet stacking” or developing excess carbon deposits on the injectors. In colder weather, it can reduce warm up time. In warmer weather, increased coolant flow and airflow across the radiator due to the increased engine fan speed can reduce the chance of overheating at idle. It can speed battery charging. High idle can maintain passenger compartment heating and cooling. But what was Ford’s purpose for designing this feature into the engine management system?
Here’s one example. Super Duty trucks are used in vehicle wrecker fleets. In order to drive the hydraulic pump that makes the tow dolly move up and down to lift a stricken vehicle, the engine speed on the Super Duty needs to be increased. An operator could put a foot on the accelerator, put a stick on the accelerator, or flip a switch and let the truck’s computer do the work. Or another. The utility bucket trucks that have a lineman repairing electric lines from a hydraulic lift arm. The hydraulic pump is driven by the truck’s engine.
There are many other reasons that you may think of for using this modification, which simply uses Ford’s own engine computer management to control your diesel’s idle speed. This modification comes from data compiled from Ford Motor Company files, and should in no way compromise the warranty on any vehicle.
How to make the high idle circuit
Use an upfitter switch, because that is one of the uses Ford designed them for. As the amperage required for control of the PTO function is very low, use AUX 4, a 10-amp circuit.
As you remember, the blunt cut wires for the upfitter switches are at the rear of the fuse panel. Select the Orange/Light Blue wire, which is controlled by the AUX 4 switch and relay. Behind the parking brake, look for another bundle of blunt cut wires. Ford calls this the Customer Access or CASC bundle (the bundle is there so the trucks can be modified by Ford approved body manufacturers). There will be 11 individual blunt cut wires, including four pass-through wires for the upfitter switch circuits. You are looking for one, a purple/light green wire. As there is not enough wire to reach from the fuse panel to the CASC bundle, you will have to make a small jumper cable. Four to eight inches, depending upon your finger dexterity, should be long enough.
Connect the Orange/Light Blue blunt cut wire from the upfitter switch wiring harness to the Purple/Light Green wire in the CASC bundle, using butt connectors and the jumper cable.
In order for the high idle to work, the engine management system must sense the following states:
Parking brake set
Transmission in Park or Neutral
Service brake not engaged
Press the parking brake, place the transmission in Park or Neutral, and then start the engine as normal. To test the circuit, bring the AUX 4 switch up. The idle speed of the engine should increase to 1200 to 1250 – RPM, even rising to as high as 2400 – RPM depending upon the state of battery charge. Release the parking brake. The idle speed should return to normal.
