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For the record, I realize that the 24v's have a factory high idle...but I don't have one, so it doesn't intrest me in the slightest.

That being said, the CC on a 12v is a vaccum cylinder hooked to the throttle linkage IIRC, so in "theory" you could use the CC to control the idle. Correct??

Not trying to offend anyone, just trying to sort through the 24v info and get to the stuff I was looking for. Will continue waiting for more opinions or possibly someone who has tried this and wishes to elaborate on their setup or idea.

Thanks Again,
Chris

LanceD

I jammed a wire into the plug that goes to the vacuum solenoid with 12volts on it. there is 3 wires that go in there, I don't remember which one did it, I had a schematic then. but one could supply maybe 3-6 volts Im guessing and make it variable with a varistor and you could adjust it. only problem is you would have to get in your truck and push the cruise button probably.

I came to the conclusion that it would be easier to buy one of those throttle cables that you turn the handle to give it more and push the button in the middle to bring it back to regular idle.

infidel

I've done this mod on a 12 valve, a '95 in fact.
There are three wires at the actuator under the battery, ground, throttle up and throttle down. What you have to do is wire in two momentary contact push button switches in the cab to supply 12v+ to the up and down wires when their respective switch is pushed. Using lower voltage accomplishes nothing as you are just controlling an all the way open or shut set of electric valves.

Problem is the the way the actuator works when the cruise control is controlling throttle is that the positive up/down pulses to the actuator are computer fast, pushing a manual button supplies voltage for too long, you either get full throttle or idle no matter how fast you try to push the button. This problem is easily solved by restricting the vacuum line to the actuator so it reacts slower. I did it by installing a piece of round plastic in the vacuum line that had a hole in it made by pushing a hot needle though. The hole needs to be very small to slow the vacuum down enough to have any degree of control with the added switches. Someone here had the bright idea of putting a nozzle extension tube from an aerosol can inside the vacuum line to restrict it.

Now with this mod up and running the downside is your cruise control will be slow to react, instead of holding right on the mph like they normally do speed will vary about 5 mph and pushing resume will take quite some time to get back up to speed if you drop out of cruise. No big deal, just use your foot to help the restricted vacuum.

Personally I prefer to just use my windshield ice scraper wedged in-between the go pedal and power seat. Seat back and forth controls rpms quite well.

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As usual, Bill comes in with exactly what I wanted to hear!!

Now, what do you think about a second CC servo wired up like this?? How many parts would I need?? Is it just the "thing" under the battery, or is it something else I don't know about??

Chris

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After re-reading your post Bill, I assume that the up and down wires come from the PCM, Right??

I'm trying to remember back to my electonics classes for something that will pulse signals.

Is there any wire that the PCM uses to sense speed for the CC, that I might be able to run to a switch and use the factory buttons to adjust it??

Thanks Again Guys,
Chris

LanceD

yea thats a good idea, how can you fool the computer to thinking you are cruising along so you can just be sitting in park, hit the cruise on button, push the accell button to bring it up?

jfpointer

Don't know if this will help, but you might look on Superlift's site to see if they have installation instructions for one of their TruSpeed units for your year truck. Seems like to work, that box has to manipulate the speed sensor signal, so the installation instructions might tell you what wire you're looking for.

infidel

The PCM uses a signal from the VSS (vehicle speed sensor) to control the cruise. Guess you could figure out how to duplicate this signal, I'm sure it's just a pulse rate. Only problem is the PCM won't let the cruise engage below 35 mph, that might make the idle higher than you want it. Also not sure how the cruise reacts to being in park/neutral if you have an auto.

How about going this route? Lil Dog has some pictures of his setup. Seems simpler
https://www.dieseltruckresource.com/...ad.php?t=82409

signature600

NV5600 for me


I like the idea of using the factory controls...it would be nice. I might try it this weekend and see how the cruise works with the vaccum signal choked!

Thanks Again for the info, Bill
Chris