I have been having some issues with installing cruise to my 1999 TJ - SE (2.5). The servo unit checks out - if I put 12v on pin 3, I see 12v on pins 1 & 2 and I have a solid ground at pin 4 in the connector. Connector Pin three is connected to the brake pedal switch with no loss, and the switch checks out OK as well. The steering wheel control buttons have been disassembled and cleaned, and all contacts come back with different resistance to ground and cycle every test now. My jeep had the plug already at the servo so I should not be missing wires in the loom. New clockspring is installed with the correct connectors. Dash test shows the cruise light works, but it will not come on with the buttons, and the cruise control will not operate. Is there a connector I may be missing between the buttons on the steering wheel and the vehicle computer? Does the computer need a reflash to know the cruise system is there? I must be missing something here... Voltage to the cruise comes from the computer after the switch tells it to turn on - so far I have not had voltage from the computer. Please let me know if there are tests I should do to narrow this down further? Thanks!
On my manual tranny there is a brake cutout and a clutch cutout and might even be a tranny neutral switch cut out all to keep cruse from Reving engine when clutch in or tranny in neutral and the brake one to keep cruise from fighting you applying the brakes
The dash light comes on with cruse on switch but of course no cruise effect till you hit set switch when moving and no light associated wit the set function
It looks like the brake switch has a couple of contacts dedicated to the cruise control - the power routes thru there. I have checked out that switch and it works as it is supposed to and has continuity to the servo. I also verified that the steering wheel switches are working. I still do not get a cruise light on my dash and no cruise control function. I know the dash light works as it comes on during the self test for the dash. Any more things I need to check? Thanks!
The jeep is a standard trans. There is no fuse for the cruise - it gets power from the main computer - thru the brake switch. Best I can figure - the steering wheel switches tell the computer to turn on, and it sends power to the brake switch. If brake is not pressed and other contacts are where they are supposed to be, power goes to the cruise. I could be wrong???
It only starts with the clutch depressed. I have a hard time thinking this could be an issue. They would not have set up the cruise control to operate only if a safety switch was bypassed. I will try tomorrow and see what comes of it. Is this fuse behind the glove box or in the power distribution near the battery in the engine compartment?
Agree if it is not currently bypassed and only starts with clutch depressed that would not be the issue but if it were bypassed it might be the issue as the PCM might be getting a signal that clutch is depressed even when it is up
Dealer is a last resort. I will probably just pretend it works before I go there.... I swore off chrysler products a few years back because the local dealers were so bad. I have had issues with ford and chevy too but nothing like the ones with chrysler. I hope it does not come to that...
To do that look at wiring diagram and unplug harness at main computer then put power to harness plug wire that computer uses to light the bulb and make sure wire lights bulb
If that is good then splice into switch input wire near computer plug and apply ground with proper resistance for on signal and see if that makes system turn on light ( have to have engine running for this)
Besides the 04 rubi I have a 98 sport with factory installed cruise and I will check if it maters if servo is plugged in to make light come on with on switch and check if in neutral or clutch affects light
A guy on JF was pre-wired, but he had to drill out the PCM connector and install the pins. The thread I posted above shows you how to do that. It's not hard to do, but you need to take your time and not let any of the other pins come out of the connector when installing the new pins. Installing Cruise Control? - JeepForum.com
With key on engine not started green cruise light will NEVER come on
With engine running jeep sitting still the on/off steering wheel switch to gels green cruise light on and off with each push and makes no difference clutch up or down and tranny neutral or in gear switch always to gels light when engine is running
As promised unplugged servo on 98 and still with engine running on/off switch toggles green cruise light on and off so check giving power to light at proper unplugged PCM harness pin and verify light lights and if it does splice into proper. pCM switch wire right near PCM plug and apply on/off grounded resistance in momentary fashion while engine running and verify light function
Then you know which wire or clock spring connection is bad
I also found the 98 servo is harder to get to to unplug as buried on bottom with 2 piece bracket much different than 04 perhaps all 98 or perhaps because of extra Cali evap emissions crap on my 98
Thanks all for your input. I will be checking the PCM plug to see if the wires are present, but I expect they are. The plug is present and wired at the servo, and the wires are present on pins 3&4 on the brake switch with continuity to the servo plug. Grounds check out. I have a hard time believing that the wires and plug would be there but not inserted into the PCM plug, but we will see. Are there differences between models relating to the steering wheel buttons? My jeep is a 99 but the donor was a 98. I am thinking that the circuit from the buttons to the pcm is the most likely suspect unless I come up with missing wires. Thanks again for your input!
Digger - your test replicates what the manual says exactly, but I have not been able to duplicate it. Gotta find the bad connection or part here....
Cuder - When I read the link, I take that he was prewired under the dash - buttons and all plugged right in, but he was missing the 4 wire connector to the servo. I could be wrong but I think that is what he was adding to the PCM plug. I will check the plug locations later today for the wire presence at those locations...
Easy to compare part numbers on part lists to see if changes98 vs 99 but as far as steering wheel switches the 98 uses older style and 2004 newer style and obvious which you need as they won't fit right into steering wheel unless correct version
I would guess you have a bad connection or wire or bad clock switch or bad on off switch
Don't worry about servo yet because even with servo not connected with engine running and properly wired switches you should be able to get green cruise light to toggle on and off
Once you get that working then if it still does not work correctly we can worry with the rest of the system
The servo does test out per the manual. I jumpered power to the #3 contact and was able to see voltage on the #1 and #2 pins, and the number 4 pin has a good ground. Also a good vacuum source. I think the servo is solid - the problem must be related to the switches or the related wiring. This was purchased from a part out where everything was working so it most likely leads to the wiring in some way.
I just checked the connectors at the PCM - all the wires shown in the manual are present on all three connectors. All the plugs have been present and all indicated wires are there. I guess next is testing continuity from the steering wheel switches to the PCM, and also the colckspring itself to verify all connections go thru intact. Please advise if there are any additional tests I should be doing while I tear it apart yet again?
Pull the connector on the right side of the ECM ( this is C3) and make sure there is a pin in the #32 hole. This is the wire that comes from the clockspring. It should be Red/Light green.
Also check the continuity from the clock spring connector to that pin.
I did not get to the continuity tests today, but all 3 connectors on the PCM had every wire listed in the service manual - nothing missing and no extras. I suspect that there is a break in the continuity somewhere, or a bad switch on the steering wheel or a bad clockspring. Hopefully I can get to it before the weekend and test a few more thing. Thanks again for all the input!