My 94 E350 short bus does not have cruise control. I plan on using it for long road trips, and it would certainly be a nice feature to have. Experience tells me driving a truck across Iowa without it blows. Is it possible to add?
Aftermarket kit would be the easiest, but they are not cheap like they used to be. Not much market for them anymore. If you try to put a factory setup on it, you have different wiring for the horn and the steering wheel to mess with.
Here is a aftermarket kit on ebay.
https://www.ebay.com/itm/253612150769
I would just grab the factory electric cruise off of a 92-94 pickup and install it into your van, it’s 7 wires and very easy to install and way better then the vacuum cruise on the earlier trucks.
Making a cc unit is no simple task, you need to program it right so it doesn’t act like an on off switch on the throttle but is also not slow at responding, your looking into PID control for that.
And a tach from road speed would be very inaccurate, better off using a factory tach sensor and making a gauge from that.
I know it's not that simple, and I am rather familiar with PID, and really want to learn more about it. I'm an electrical engineering student, so this is exactly the kind of stuff I do. having personal projects I can swing as class projects is a great way to get free (well, with thousands in tuition...) parts and advice. I think it would be an interesting project; I'm going for learning, not necessarily the best / cheapest solution.
I was absolutely planning on using the factory tach sensor for that aspect. I need to find the specs of the output or get a scope on it, but that should be a very easy project.
I’m definitely no EE, just your standard tinkerer, I do know a bit about the cruise control that ford uses (not so much on the programming).
Minuumin speed input is 30mph before turning on, max speed was up around 212mph (why!?! Ford???) before it kicked out. They use a stepper motor driving a electromagnetic clutch, spring loaded drum for the speedo cable, the clutch is engaged and stays engaged during cruise control and disangeges when either the speed is below 30mph, brake is pressed, brake pressure sensor measures over 8-10psi, speed is 20mph above or below the set point or you hit the off button. They don’t use the stepper to return the throttle cable, the spring in the drum does that for a quick release of the throttle. Speed input is the standard 8000 pulse/ per mile.
That’s what I found out playing around with a unit on the bench, hope that helps you for your project.
Alright, I will definitely look into the aftermarket units. Also considering building one myself.