So the truck in question is a 1999 dodge ram 1500 reg cab short box 2wd. I put a 12 valve and 47re in it a while back. I used the 98 12v harness and computer so everything was plug and play. I had been more focusing on making it a little stop light to stop light toy, and got it how I want but decided to get the creature comforts working so I tackled the ac. Got that going the other day with the addition of some new lines and a condenser from a parts truck out back. Great, now I'm not sweatin like a hog while driving. Last on the list is the cruise control. There's some Friday night drags 2 hrs from my place and driving long distance sucks without cruise so I'm hoping to get that going as well. First off, when the cruise button was pushed "on" I never got a light on on the dash. So, first off I checked the brake switch, seems to be functioning. Next moved to the clock spring, seemed to have continuity. (I have no schematics or diagrams or specs on ohm readings, basically just probing around and trying to make sense of things.) so next is the switches. I pulled the air bag and the switch for the on off and set tested at xx ohms, pushed the button and it changed, ok so that works. Well just for giggles I went and pulled the switch from a parts truck and tested that and the ohms were way different, so I threw that switch in and low and behold the cruise light now comes on when the on is pushed. Great! However, the abs and break light comes on, so I know I have to get that taken care of before the cruise will set. The transmission output sensor is new, and correct ohms, the rear end sensors is new and correct ohms, and there is no front abs. So I swapped the abs module from parts truck, no dice. Hmmm I got to thinking and maybe the truck I used the computer from was a 4 wheel abs truck, so I called dodge with the Vin from that parts truck and they confirmed that it was rear wheel abs. Back to square one, we'll out of ideas I decided to throw in another 98 12v computer from another parts truck that I looked to make sure what rear wheel abs and sure enough now my abs light is off! So Idk if the other ecm was bad or was actually a 4 wheel abs truck, either way I got that figured out. So now my cruise should work! Nope. Light comes on but will not set. So I pulled the servo off and disassembled it and started putting power and ground to the servo solenoids and was able to get the pull, hold, and bleed to all function so the electric part of the servo is goo, put it back together and hooked vacuum to it and did my jumper wires and it will hold whatever position I put it at. So the servo is good. So I started the truck, turned cruise on and checked for power at the servo plug but there is none. Less than a volt across most of the pins, maybe all. But nothing worth talking about, nothing that would ever control anything. So my question is, does anyone know what the ecm looks at for the cruise to work? What I know is brake switch, signal from steering wheel switch, something from abs saying it is working, and I'd assume something from the n safety switch? Anything else? Maybe someone who's done a auto to manual swap can give light on the n safety part of cruise? Anyone have a cruise wiring diagram? Thanks in advance! Also, can I post this in the 98-02 24v forum, seens how the interior and wiring is more like that than the 94-97 there probably aren't a ton of people with 98 12v. I just don't wanna get a ticket from the internet cops for posting it twice, you know, I'm sure that's a pretty serious offense! But desperate times call for desperate actions.
Need some advice on the cruise, in my ram 1500 (yes it's a cummins...)
- Thread starter brixen348
- Start date
You are correct it needs to be 36 or faster. I would assume one pin would be energized at a stand still though and then as it sees 36, the set button is pushed it would ground out the correct pin. But that's just a guess. When exploring the servo, I learned that's how it works, there's one power pin, and the other 3 get grounded as needed. So power comes in, the pull solenoid gets grounded then the hold one gets grounded then to slow down the bleed gets grounded. But maybe the power doesn't come on till 36 I guess I should rig up a light and go for a drive huh lol
Found out the power supply wire for the servo comes from the pcm and goes through the brake switch and then to the servo. I have power at the servo on pin 3 so that is good. Pin 4 at the servo is a ground, that too is good. That leaves pin 1 and 2, those are the controls coming from the pcm. So either my problem is in the switches/wires to pcm, or the pcm is not seeing something it needs to enable cruise set (speed, rpm, whatever else it looks for) so, does anyone know for sure what the pcm looks for to enable the cruise to set? And does anyone have the pin ohm test specs for the switches on the steering wheel? I found test procedures but they are "connect drb scan tool and press set button multiple times while watching scan tool to see if it sets" well I don't have one of those, and the switches are momentary resistance switches so they gotta be testable. Or if someone has some known good switches and wants to test them, that'd be awesome. It takes about 2 min to get them out (if you work slowly at it) thanks in advance!