PDA

View Full Version : Retrofit throttle/cruise control/high idle circuit



markrinker
01-30-2004, 10:34
I am sure this topic has been tackled before for 1994 models without cruise control...

I am looking for a simple circuit designed to tell my ECM a particular throttle setting without actually having my foot on the pedal. An on/off button combined with potentiometer and the whole thing deactivated manually or by the brake light switch.

Should work good for cruising and high idle during warm-up.

Anyone?

cruzer
01-30-2004, 13:39
Mark, in a past post somewhere, IIRC there was a member whose turn signal lever broke. He did not have cruise. He had a gasser parts truck and pulled the turn signal lever, which had cruise. He installed the lever and the cruise worked. I don't know what yrs the trucks were.FYI

ucdavis
01-30-2004, 21:11
Wierd as what Cruzer said sounds, I'm inclined to believe that it'd work. '94 CC is handled by the PCM which meets out all injection control signals (the accel pedal is just a system of 3 potentiometers which feed signal to the PCM by wire, no hard cable connection to any fuel control). Since the CC is part of the PCM program, I find it hard to believe that GM sold trucks w/specially de-tuned PCMs that eliminated CC. So if you got the gizmo that feeds CC signal to the PCM, it will probably extend the required signals to the IP. Wouldn't cost much to try it.

[ 01-31-2004, 01:13 PM: Message edited by: ucdavis ]

Bobbie Martin
01-31-2004, 05:21
An on/off button combined with potentiometer and the whole thing deactivated manually or by the brake light switch.
If you are planning on replicating the APP signal, its not that simple. The APP provides 3 separate and differently scaled outputs. You must have at least two and they must be in proper relationship to each other or the PCM will not be happy at all! I have more experience than I care to in this area and the APP/PCM relationship must be very close to factory or there will be all kinds of problems. I'm not saying its not possible, but very difficult.
However, if you are just trying to add cruise, its pretty easy. There are only 3 inputs to the PCM for the cruise, On/Off, Set/Coast & Resume/Accelerate. The easiest way would be to get a cruise turn signal stalk from a junkyard. I can't say 100%, but I am reasonably certain any GM cruise stalk would provide the correct electrical signals. If the 94 had the old style removable stalk, there are dozens of GM vehicles you could get a stalk from. Then its just a simple matter of wiring it up. I wouldn't be surprised if the wires are already at the steering column. If you need wiring diagram info, let me know.
For the fast idle, JK has instructions on how to do this on his website.

CareyWeber
01-31-2004, 08:35
The PTO function is there and can be used for warm ups, but as soon as you do any of the following it cancels the PTO speed settings:
Touch the brake
put the truck in gear (automatics for sure manuals I don't know)

The settings are 1000/1300/1600 rpm IIRC

John Kenndey's website in the tech section has the how-to about it.

Carey

KevinsOffroad.com
01-19-2005, 21:31
BTT. Mark or anyone...did someone here verify that the '94 turn signal stalk will activate cruise on a non-cruised truck? I have a '96 F engine and a cramped leg.

Thanks,
Kevin

markrinker
01-20-2005, 05:42
I haven't tried it yet.

diesel65
01-20-2005, 17:28
Kevin,
You will need to replace the whole turn signal switch assy to get the cruise switch.
It should be a plug and play, no reprogramming needed to activate the cruise control.
You could just install three switches in the dash, one on-off and two momentary push button.
If you want to go that route let me know and I will advise you.