No cruise man!

[Atom]

I took appart my dash the other day and now the cruise control does not work! I have a 1996 SE with the controls in the steering wheel. The little green light by the on/off button still comes on but nothing happens! I checked the vacuum lines and they were all fine as well as my bottle behind the frount bumper. I did not see any fuses for it, so I am baffled! Anyone have any ideas?

 

[kbeckman]

If you can turn on the cruise control, then your wiring is hooked up. There are 3 wires that go to the control at the steering wheel, ground, +12V and the switch signal. The fact that the light turns on when you turn on the cruise control is telling me that's hooked up, and working.

The next place to look is the stop lamp switch. The Yellow/Red wire supplies +12V to this switch, then turns into Dark Blue/Red on the other side, and goes all the way to the Cruise Control Servo. The Black wire is ground, and turns into White/Pink on the other side of the switch. White/Pink goes back to the computer (plus the TCM and shifter interlock).

If you were messing around in the instrument panel, the most likely culprit is the connector C114, which has all the wires for the cruise. It's a Black colored connector in the center of instrument panel, and has 16 pins on it (8 on each side). If you have ABS, it's right under the ABS controller. Pull it apart and make sure all the pins are good, and pushed in all the way.

The wires for Cruise in C114 are:

White/Light Green
Yellow/Red
Dark Blue/Red
White/Pink

Make sure your speed sensor is hooked up. It's on the back of the transfer case (or transmission on 2WD).

 

[Atom]

Thanks

Sweet- thanks thats the info I needed! I did get the cruise to work for just a second the other night when I put the tilt in the lowest position. So this tells me I either have a pinched wire (one of the ones coming out of the control- I now know the colors) or one of the plug ins are loose! Thanks for the info!

 

[kbeckman]

The control in the wheel comes out real EZ. Just remove the 2 screws right behind the control, and it will drop right out. The 3 wires for the control are:

Yellow/Red - +12V
White - Switch
Black - Ground

The 4th wire is for the horn.

There are no other connectors in the steering column, as the wires go right to C114.

You can test the buttons with an ohm meter between ground and switch (inside 2 pins on the control). It looks like this:

. . . . <- Put Ohm meter on pins 2 and 3
1 2 3 4

As you hold a button, you will measure:

On/Off - 909 Ohms
Set/Coast - 6.65K Ohms
Resume/Accelerate - 15.4K Ohms

The measurements should be close to this +/- 2%.

Another good check is to meaure the voltages at ground and +12V. Use a good chassis ground, and measure the voltage to the black wire on the control. It should be very low, like 0.1V or less. Also measure the +12V wire it should be above 12.0V.

 

[Atom]

Thanks again

I wish you lived next door! The info is great- I found a whole cruise kit on ebay for $35 and it should be here shortly. So I will pull it appart and check everything this afternoon- and if I need new parts I will have them. I hope it is an easy fix. Thanks- I will keep you up dated, please keep an eye on this post in case I have some questions when I take it apart! Sounds like you have done this before!

 

[Atom]

Ok kbeckman- I tested the switch and my ohm meter read within 2 or 3 ohms of all the values you gave me. The black wire on the C114 read less than 2 volts but the yellow wire never read any volts out of the mV reading. I also found the 8 plug connector under the dash and all of the pins were in order. So can you help with why the yellow does not have 12V? The voltage must be enough to turn on the green light on the controls? And is there a way to activate the actuator for the cruise to see if it works? THanks for your help- and yes I am lost!!!

 

[Atom]

Ok now I got a good ground and found that I do have 12-13volts on the yellow wire- is the high reading bad? So now I am really lost! I guess I will just start replacing parts and see if it fixes it? THanks

 

[kbeckman]

Did you check the stop switch on the brake? Remember there are 4 wires there as well, in 2 circuits. Also make sure the speed sensor is hooked up on the transfer case. I believe the speedo uses this as well, so I assume if the speedo works it's hooked up!

The 12-13V on yellow is good. It will read whatever your battery voltage is. The control sounds good too.

"less than 2 volts" on the ground may be your problem. This is a ground wire that goes back to your computer, and should really be ground (0 volts). When you say, now you have a good ground, what do you mean?

It's got to be something in the dash or steering column, since you said you were messing with the dash, and you got it to work by moving the tilt on the wheel, but I've seen weirder coincidences. There are 2 other wires on the servo under the hood that go to the computer. They are:

Tan/Red - Vacuum Solenoid Control
Light Green/Red - Vent Solenoid Control

I think you said you checked for vacuum at the servo.

 

[Atom]

Thanks for the response- What I had actually done was remove the instrument panel to put in the white guages. THe problem is that I hardly ever use the cruise and I am not sure I made the problem when I took every thing appart or if it was that way before and I just never noticed it. What I meant by a good ground was that before I was not using a good ground on the body and thats why I did not get 12volts from the yellow wire.

I still need to check the stop switch on the brake- but I think it works because brake lights work and my transmission allows me to go out of park. The speed sensor is hooked up-speedo works and I checked the transfer case and no problems with the wiring or anything.

The only 2 things I can think of is that maybe there is a problem with the "thing" that tells the cruise that I am traveling at a speed over 35mph.This "thing" I have no idea what it is or how it works.

Or-I checked the vacuum at the servo, but I am unsure that the servo is actually getting signal or if it is working at all. Can I just jump a wire from the battery to the servo to test the servo- or is 12volts too much?
What do you think? Thanks again

 

[kbeckman]

The brake switch wires that actually go to the servo are DIFFERENT than the ones running the stop lights, and controlling the shifter.

The Yellow/Red wire comes from the computer, goes up to the control in the steering wheel, and goes to the stop switch. From the other side of the stop switch it turns into a Dark Blue/Red wire and goes right to the Servo. There should be +12V on this wire.

I would'nt bypass any of these wires and try and run it directly from +12V, you'll burn something up.

The answer is in front of us, we just have to figure it out.

You should be able to start the Jeep, turn on the cruise LED, and meter for +12V at the Dark Blue/Red wire on pin #3 on the Servo. If it's there, then the switch is probably OK.

The "Thing" is the speed sensor, and you might be on to something here. The speed sensor has 3 wires:

Black/Light Blue = Ground
Orange = +5V DC
White/Orange = Speed Signal

The White/Orange wire goes to the computer, plus up to the instrument cluster right into the speedometer. Are you sure the speedometer working correctly?

If the brake switch checks out, I'd unplug the White/Orange wire somehow (It goes through C114) and see if something in the instrument cluster is causing all of this.