Well guys I finally fixed my cruise control for good now, I've been driving around all day using it and it works everytime now. The problem was the speed control servo, I replaced it with one in I got out of an 02 5.9 RAM, I decided to take it from there instead of the 99 Durango because I figured since the PCM checks this thing over, the internals and even solenoid resistance should match much closer by year, but all the units in the junkyard from RAMs to neons looked the same to me so they might be.

Basically the reason the cruise only turned on once with the engine was running was the PCM was checking out the solenoids inside making sure everything was working and it found a fault so it didn't engage the cruise and the second time you turned it on it already know there was a problem so it shut off right away, the PCM doesn't do this test when the engine is off because there is no vacuum for it. The 4 pins on the unit are ground, then the other 3 are only directly connected to the PCM (1 power feed running through the brake lamp switch, then 1 vent and 1 vacuum line which are controlable grounds from the PCM. I took my old servo apart and the vent solenoid was indeed an open circuit so that was the fault in whole the system. It's a rare problem that this happens which made it difficult to locate the problem.

Hopefully this helps anyone with this crazy problem in the future, but brake lamp switches are much more likely to fail first. Thanks everyone for all the help.

 

Thanks for the update!

 

I have been working on this problem for 5 years, been to dealer 4 times. First they said it was a servo. I have 3 servos and 3 dodges all servos work fine on 2 dodges and none work on problem car. I tested resistance thru clock spring at the computer terminals thereby checking the whole harness. I tested and adjusted the brake switch several times. Everything is good. The computer is obviously turning cruise off and locking it out. I believe the computer is picking up some fault, real or imagined, and after so many times of finding it, the computer just locks out the cruise. I can tell you, Chrysler is hiding the codes, just like the ABS, If they clear the computer with their machine the cruise will work for a while. If I or AutoZone clear the codes it won't work. Each time I take it to the dealer they find some little thing and claim that is the cause. They clear the computer and claim they fixed it. After a week or two the computer software counts enough "faults" and locks the cruise out again. I called their corporate hot line and they just made excuses and told me to take to the dealer. I wish I could give more hope. I never thought I would consider buying a foreign car, but after this I am about ready.

 

First off the autozone code reader is not nearly as powerful or as capable as the DRB-III the dealer uses. Next is there probably is a problem that could be fixed, they are just to lazy to trace it down like Evon has. All manufacturers "hide the abs codes", that way you take it to a shop to have the work done or diagnosed as a safety precaution since abs is for your safety. Most shops don't charge much to give you the abs codes either and you can do the work yourself. If this is the only problem with your durango, why buy foreign may I ask?

 

Sorry to hijack but I need help.

I've been searching all over the net for this same topic for my 04 Dakota and finally it seems I found some guys who know what they're talking about.

Could you take a look at my thread? I think I've narrowed the issue down to "no power to the servo" but now I'm stumped. My post clearly explains the things I've tried.

I bought the truck a week ago knowing the CC didn't work. The PO didn't say how long it had been out and I didn't ask.

Link - My CC Thread

 

This is kind of an old thread, but anyway I have my personal experience to add to this. I had the exact problem with my truck for about 2 years, I tested switches, traced wires and couldn't figure it out. Then an unrelated "no bus" issue caused me to have to replace the PCM. Get it in and running, take it for a drive and presto cruise control works like new, no problems whatsoever. Now I hope this is not what is causing your issue as it is no cheap fix. However, if you have the exact issues described in the original post i presume this is the cause. Anyway I made it two years without CC so it just depends how much you need it, its not like the truck is non-operational without it.

 

It's not urgent that I have it. I hate being stumped and just would like to solve it.

Can anyone answer this regarding the brake lamp switch?
"Try jumping terminals 1 and 4 together and then see if you have power at the cruise control servo."4-V32 20YL/RD SPEED CONTROL SUPPLY


I get power to the servo when jumping so I know the wiring works. I bought a new switch and it didn't solve my issue.