7.3 with BD exhaust brake.. warm up??
#1
#3
#4
So far i have been using my Pace brake to warm mine up quicker and the emc will automatically increase the idle to 900-1000.
#5
With the use of an Auxiliary Idle Controller, Homebrew version is a linear potentiometer wired into the throttle position switch. Or there was a Ford model for PTO control.
https://www.ford-trucks.com/forums/5...e-control.html
https://www.ford-trucks.com/forums/5...e-control.html
#6
With the use of an Auxiliary Idle Controller, Homebrew version is a linear potentiometer wired into the throttle position switch. Or there was a Ford model for PTO control.
https://www.ford-trucks.com/forums/5...e-control.html
https://www.ford-trucks.com/forums/5...e-control.html
Thats what i was figuring but never hurts to ask, Thanks
#7
The Blue w/yellow wire is the PTO enable circuit. When that wire is fed 12vdc then the PCM will think a PTO is active and up the idle. There are a few conditions that must be met such as the trans must be in park (auto), parking brake set, throttle position at idle and brake lights are not illuminated. If those conditions are met then the PCM will up the idle to the preset speed (about 1200 rpm).
The Blue w/pink wire has keyed 12vdc so that can be your power source if you would like. Wire an off/on switch between the blue w/pink and blue w/yellow wire and you will have your fast idle.
(pre '98 wire color is Red w/yellow...'99-'01 is Blue w/pink and '02 thru '04 is White w/blue)
If your switch has a light then you can wire the third terminal to ground to allow the light to illuminate when the fast idle is active. If the light is an LED, then a series resistor needs to be added (according to these instructions that I got from bobmiers) Thanks Bob!
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#10
Me too. Simple is better sometimes.
For the longest time I used to think that only cab and chassis trucks has the PTO wires but I checked my wife's 2000 F250 and found the wires so maybe they are on all SD trucks?
1200 rpm works for most all situations but if you really want the ability to adjust the fast idle speed then find yourself a 5-10 ohm potentiometer and use the AIC connector behind the access panel. There are four wires in that connector. One is 12v power, another is ground and the last two are a bit of a mystery to me. The book says they are SCP bus positive and SCP bus negative. I need to confirm but I think one of those wires is Signal Reference Voltage 5vdc (SCP bus +) and the other is the PTO active signal to the PCM. If this is true, then connect the VREF to the potentimeter as primary power and then feed the regulated power back to the (SCP -) wire.
Less than .5 volts will give 1200 rpm idle speed. .5 thru 4.5 would give a range up through 2500 and over 4.5 will be normal idle. I'll attach the AIC manual pages that leads me to think this might work...(page 6 has the voltage table for rpm ranges)
In your case, since you have the PacBrake...it already might be utilizing the PTOC wires. If so, and if you want your own manual fast idle on/off switch then you are going to have to incorporate some diodes to make sure you don't backfeed power to the Pacbrake while using the fast idle switch or vice-versa.
For the longest time I used to think that only cab and chassis trucks has the PTO wires but I checked my wife's 2000 F250 and found the wires so maybe they are on all SD trucks?
1200 rpm works for most all situations but if you really want the ability to adjust the fast idle speed then find yourself a 5-10 ohm potentiometer and use the AIC connector behind the access panel. There are four wires in that connector. One is 12v power, another is ground and the last two are a bit of a mystery to me. The book says they are SCP bus positive and SCP bus negative. I need to confirm but I think one of those wires is Signal Reference Voltage 5vdc (SCP bus +) and the other is the PTO active signal to the PCM. If this is true, then connect the VREF to the potentimeter as primary power and then feed the regulated power back to the (SCP -) wire.
Less than .5 volts will give 1200 rpm idle speed. .5 thru 4.5 would give a range up through 2500 and over 4.5 will be normal idle. I'll attach the AIC manual pages that leads me to think this might work...(page 6 has the voltage table for rpm ranges)
In your case, since you have the PacBrake...it already might be utilizing the PTOC wires. If so, and if you want your own manual fast idle on/off switch then you are going to have to incorporate some diodes to make sure you don't backfeed power to the Pacbrake while using the fast idle switch or vice-versa.
#11
....
1200 rpm works for most all situations but if you really want the ability to adjust the fast idle speed then find yourself a 5-10 ohm potentiometer and use the AIC connector behind the access panel. There are four wires in that connector. One is 12v power, another is ground and the last two are a bit of a mystery to me. The book says they are SCP bus positive and SCP bus negative. I need to confirm but I think one of those wires is Signal Reference Voltage 5vdc (SCP bus +) and the other is the PTO active signal to the PCM. ....
1200 rpm works for most all situations but if you really want the ability to adjust the fast idle speed then find yourself a 5-10 ohm potentiometer and use the AIC connector behind the access panel. There are four wires in that connector. One is 12v power, another is ground and the last two are a bit of a mystery to me. The book says they are SCP bus positive and SCP bus negative. I need to confirm but I think one of those wires is Signal Reference Voltage 5vdc (SCP bus +) and the other is the PTO active signal to the PCM. ....
I thought I'd follow up on this since I messed around with the wiring this weekend. Unfortunately my idea above won't work. Turns out that SCP bus +- stands for Standard Corporate Protocol positive and negative. These wires are twisted pair wires similar to ethernet wires for computers and used for module to module communication (such as PCM to IDM or GEM etc). It looks like the Axillary Idle Control box is treated as a module and that connector is used for it's module to module communication with the PCM.
So, long story short. You can wire in a switch between the PTO control wires found under the dash for fast idle but it won't be adjustable. Of course the parking brake must be set, no brake lights (foot off brake) and foot off throttle.
For variable fast idle, then using a 5-10 ohm potentiometer inline with the TPS is the next best idea short of using the actual Ford AIC module.
Here is a photo showing where the PCM enable and 12v wires can be found.
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