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Does anyone know how the A.S.S. switch works? Is it a NO (Normally Open) relay that toggles between NO and NC (normally closed) each time you press it? If so, we could use another NC relay to reverse its function. The bottom diagram shows how their switch works now (I think). The upper diagram shows how we can reverse its function with a single SPST NC relay. (I used a speaker diagram to represent the A.S.S. device.) You cut the wire after the switch, run the switch side to the relay activator, run the other cut wire side to 12v+, and run the other side of the relay activator to 12v-, voila. (Note that when their switch is off, A.S.S. is active. When their switch is off, ours is on, deactivating A.S.S. When their switch is on, ours is off, activating A.S.S. That exactly reverses the function of the A.S.S. switch.) (If their switch is merely a momentary contact switch, we would need a latching relay.)
I haven't looked at the diagrams, but I'm pretty certain all of those buttons are momentary switches. When you press it, you send an input to the computer - that's what turns the function off.
I haven't looked at the diagrams, but I'm pretty certain all of those buttons are momentary switches. When you press it, you send an input to the computer - that's what turns the function off.
In that case, this latching relay should work. We would come off of 56b (the NC pin). Of course, we need a latching relay that does not require reversing polarity to make it work. This relay requires the ground to be switched instead of the hot wire. That would necessitate a somewhat different wiring path, but not tremendously so. The Ford switch would be taken completely out of the hot wire section, and wired back in on the ground wire section.
The computer is likely looking for a pulse, not a constant. To do it right, you'd have to do something like a 555 in a one-shot configuration to apply the pulse.
I think it's looking for input "on" to toggle *** on/off. I can only speak for my 2015 but pressing and holding the button toggles the *** to on or off. That's why the jumper method works.
The NC relay contact to reverse logic would probably work fine to disable on startup and you still retain the option to turn it back on.
With it you can configure it to send a single pulse when the truck is started kicking the system into 'off' mode, then subsequent presses of the button will allow you to cycle between on and off.
As a side note, the same device can be used to change the "default" drive mode. Same idea, it can pulse the button automatically on start selecting the mode you want.
The NC relay contact to reverse logic would probably work fine to disable on startup and you still retain the option to turn it back on.
That is exactly what I would like to do. While I don't like A.S.S., I can see utility in heavy stop and go traffic or in severe city traffic. I currently have it disabled with ForScan, but if we could have it automagically reverse on engine start (initially be OFF rather than ON), I would leave it functional and turn it on whenever I felt it was useful. I am not an electronics person, and don't understand the terminology, but if someone who does understand how to do it, I would be interested.
With it you can configure it to send a single pulse when the truck is started kicking the system into 'off' mode, then subsequent presses of the button will allow you to cycle between on and off.
As a side note, the same device can be used to change the "default" drive mode. Same idea, it can pulse the button automatically on start selecting the mode you want.
That would be perfect. Unfortunately, I have no electronics knowledge. I would need "connect the blue wire to the red wire" type instructions.
02-03-2018, 10:19 AM
Reversing A.S.S. switch function
