Welcome to Just Answer,
How about the horn, does it work? Do you have an airbag light on? Any of these would indicate beyond a doubt you have a clockspring problem. This component supplies an electrical path to these sytems while allowing the rotation of the steering wheel. If you don't have a horn or airbag issue this does not necessarily rule out the clockspring.
Check the vacuum lines from the speed control servo to the vacuum reservoir in the cowl under the wipers and the line from the reservoir to the vacuum source.
Let me know if you need more info,
The servo has 3 solenoids and a vacuum chamber, the PCM controls the solenoids according to vehicle operating conditions and switch inputs. The switchs are MUX switches which means the PCM sends a 5 volt reference through the switch and each switch setting has a different resistance. The PCM sees a momentary voltage drop when a function is selected a determines if criteria is correct for the requested function.
Changing the 5.9 thermostat is pretty invasive cxompared to a 4.7. Did you make sure the servo is still connected to the throttle? Is the cable in good condition, make sure its not kinked or damaged. It sounds like you checked most of the possibilities as far as basics. Is the servo securely mounted?
Have you driven the vehicle since the cruise light went out? It needs to be in drive to operate. 22 inches of vacuum is plenty. If you are still in the town that did the thermostat work see if you can at least get them to pull codes and see if any speed control trouble codes are set. This will at least give us a place to start. Normally the alternator is moved when replacing the thermostat on the 5.9, make sure there is no wiring pinched around the alternator.
Let me know if you get any more info,
Cycle the ignition key on-off-on-off-on and tell me if the odometer displays any codes.
The servo's power is supplied by the PCM and the steering wheel switchs 5 volt reference is also supplied by the PCM. I don't see many cruise control problems that are not clockspring related.
Just clearing a code would not affect cruise control operation, either they did something mechanically, broke something or it is total coincedence. Check the actual wires on the servo and see if they can be pushed into the connector, the tech may have leaned on a harness and pulled a terminal loose. Try the same with the PCM behind the air cleaner housing.
Unfortunately this is a system that is easily diagnosed with a Chrysler scan tool. Do you have a test light? We can check power at a couple of points if you can get a hold of one, you can get a cheap one at any parts store.
Keep in touch,
Check violet and yellow wire at brake switch connector. If you have power here you will need a brake switch.
The brake lamp switch can be tested with an ohm-meter. The ohmmeter is used to check continuity between the pin terminals.SWITCH CIRCUIT IDENTIFICATION
SWITCH CONTINUITY TEST NOTE: Disconnect switch harness before testing switch continuity.With switch plunger extended, attach test leads to pins 1 and 2. Replace switch if meter indicates no continuity.With switch plunger retracted, attach test leads to pins 3 and 4. Replace switch if meter indicates no continuity.With switch plunger retracted, attach test leads to pins 5 and 6. Replace switch if meter indicates no continuity.
Let me know if this gets you anywhere,
Thanks for the input Tim we discussed the clockspring in a previous post, the horn does work, no airbag light, no codes. It appears we're having an issue getting power to the servo.
Give some time to go over the info you gave me, I am at work right now and I don't have the capabilities I have at home as far as sending you diagrams and such, the techs terminals are pretty useless for that kind of thing. We're only here a 1/2 day, then a 30 mile ride home. I will look over your data while I am hereand have something for you as soon as I can.
Are you having any speedometer issues? I have to check, the speedo runs of a sensor in the differential. There are speed sensors in the tranny, the only common thread would be vehicle speed if the truck is equipped with rolling door locks, that is it locks automatically at a certain speed. That wouldn,t explain the lack of power at the servo.
Things got hectic on me I am still working on the last info you gave me and the door locks may be a good clue. Chrysler electrical is interesting, they spend alot of time sending info from module to module until they get to the end of the chain and the final module makes a decision.
I'll get back to you,
Heres something to check,
I was talking to another tech at work, and a Just Answer expert sent me a message verifying this. You have a heat pump on the passenger side of the engine compartment that is prone to leaking coolant into the wiring harness. Check this pump for leakage and inspect the harness and bulkhead connector for corrosion. The coolant can use the harness as a wick and cause any number of problems.
Look this over and let me know,
DATE: July 18, 2003
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 08-041-00, DATED DEC. 15, 2000, WHICH SHOULD BE REMOVED FROM YOUR FILES. ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS**. THE REVISION ADDS 2002 AND 2003 VEHICLES AND REVISES THE PARTS TABLE.
The door locks will intermittently lock and/or unlock without any activation of the power door lock switch or a clicking sound may be heard coming from the power door locks (repeated locking or repeated unlocking). The condition may occur more frequently in damp conditions such as driving the vehicle in the rain or taking the vehicle through a car wash.
Vehicles that demonstrate this condition may have water weeping into the door/liftgate lock cylinder switches causing the switch to intermittently short across the internal circuit. This in turn may signal the Central Timer Module (CTM) to activate the power door locks. Because of the nature of this problem, it is extremely difficult to diagnose this condition. Therefore, customers that indicate their doors intermittently lock and unlock without having the door lock switch activated or customers that indicate they hear a repeated clicking noise coming from the door locks should have the Repair Procedure performed on their vehicle.
This TSB may help with the door lock problem, the Durangos also have problems with water leaking into the B-pillar (between front and rear doors) across the top of the door and down into the kick panel getting water in the Central Timer Module (CTM) causing issues.
This can be hard to track down as there will be no signs of water after it dries, sometimes you can take the CTM out and remove the cover and see where water has run across the circuit board.
As far as the cruise goes, I am not leaning towards the clockspring. The reason is this, if I understand you correctly you wer driving down the road and the cruise just quit. We know you were not getting power to the servo. The switch that turns the cruise on and off is not like a light switch that provides a mechanical connection for current to flow through. When you press the button it sends a voltage signal to the PCM for as long as you have the button depressed. The PCM sees this voltage and internally switches on the power to the servo. If you have power on the yellow /red wire and nothing to the servo the only thing between these to points is the brake switch. You also stated it started working again after you checked the brake switch. Try wiggling the connector at the brake switch and see if it starts working again. It could be a clockspring, it is a common problem, it just doesn't fit with the lack of power at the servo.