1999 Dodge Ram Cruise control problem solved

I own a 1999 Dodge Ram 2500 diesel and the cruise control stopped working, the cruise light would come on the dash but the cruise would not set.

I did a lot of reading in the forum and the information in here was very helpful in helping me figure out the problem so I thought, what the hell, I’ll share what I found and hopefully it’ll help some other guy having issues.

When I would turn on the cruise control, it would engage and the light would come on the dash, but when I set it…it would disengage on it’s own going down the road …eventually it stopped setting all together even thou the cruise light was still on.

Come to find out, one of the little plastic holder things that secures the wiring harness to the firewall had popped out and the harness was ever so slightly wiggling around while driving down the road. This slight movement slowly rubbed a wire just under the control module on the right finder raw and it was shorting out. Apparently the short was telling the cruise control not to set somehow….once I found the raw wire and fixed it…problem solved.

Took a little time to find it, just kept looking around and reading on the forum. Change the brake switch, cleaned the diaphragm thing under the battery tray, checked all the fuses, checked all the vacuum lines, slowly worked my way down the wires checking them out and stumbled on the problem.

Went to wal-mart and purchased a container of plastic tie wraps….nothing under there is moving around anymore…nothing floundering in the wind…LOL…don’t feel like hunting that rabbit again.

 

Good job! Also good info, thanks for posting.

 

You’re welcome Charlie, I’m not going to lie…it took about 2 ½ days for me to find the problem tinkering with the truck on and off in my spare time.

I’ve only had this truck for about 2 months now, this is my first Dodge Ram and my FIRST diesel engine, also I purchased the truck used so I’m learning everything from scratch with nothing but the internet to help out.

Normally I don’t participate in forums, but the info being shared up in here really compelled me to join in, I don’t know much about nothing…so if I fixed the problem on my own…it really says a lot about the info up in here. I just wanted to give a little back and to say THANK YOU GUYS for participating.

 

You've motivated me to search for the cause of my loss of cc. It didn't work when I purchased the truck eight months ago. No light on dash either. Could you post some of the links you went through to diagnose? Or just give a quick to-do list. My computer is down and its hard to search on the phone. Thanks!

 

Good job getting it figured out. I highly suggest you post this fix in the oil burner section here at DF. As I could be wrong , but , the diesel is electric CC, as apposed to vacuum on a gas truck. Either way, wrong or not, I'd still post the fix in the cummins section.

 

The first thing you want to do is follow the vacuum line from your CC servo under the battery to the throttle. Probably 3 out of 4 times it is that line being broken some place that is the culprit. The elbow where the vacuum line connects to the servo is a very common breaking point because the battery drips acid down there onto the line and servo.

 

+1. But I'm not sure that holds true for an oil burner. Like I said, I could be wrong. Not to mention, he does not have a throttle body. .

 

First off, I apologize if I posted in the wrong place on the original posting. When I started out, I simply googled 1999 dodge ram 2500 cruise control and multiple responses to the search came from this forum so I would check them out. Some of them would apply to my truck and several of them didn’t…had to kind of sift through the information to figure out things.

I just figured that something was NOT telling the cc to engage OR something was telling it NOT to engage. Because I had the “cruise” light on the dash working and no other lights on the dash on I just assumed that the Clock spring was good. Also, because it worked fine for a while then intermittent I also made the assumption that the switches on the steering wheel was working. Let me see if I can layout my list of assumptions better.

1) Switches working fine at first……probably still ok because when they worked they worked fine.

2) Clock spring ok basically for the same reason….plus no other lights or problems besides cc setting.

3) Vacuum lines ok because when working intermittently…working fine until it don’t. I still check them and if anything looked suspicious I replaced with new line.

4) In my mind, I just knew once I got the battery out that I would find some damaged wires or something down there by the diaphragm or inside of it. Nothing, so I cleaned it up real good….there is a video up in here someplace that shows exactly how to clean it up.

5) Secondly, after that, I said well…the brake switch is the problem…so I changed it….BAM …nothing. That was big big let down for me…LOL I just knew I had it whipped.

6) After that, I started checking the wires…I reexamined the wires under the battery…I examined the wires under the dash by the clutch and brake peddle. Actually found one down there that the clutch had rubbed pretty good…from repeated pushing. Fixed it up and got it clear from the peddle…Nothing.

7) I had seen on one of the wiring diagrams that I looked at that the speed sensor could also tell the cc NOT to engage…so I started hunting for it. Figured I would replace it next if I could find it, so I started tracing down the harness to find this thing.

8)Pulled the air filter to check out the wires at the control module on the right finder firewall, that side of the wiring harness was kind of flopping around over there from the little plastic thing that holds it being broken…so I figured I would secure it while I was there….THAT’S when I stumbled across the naked wire that was shorting out on the finder. Fixed that wire up real good secured the harness, crossed my fingers, and it worked great. Got to admit, I’m still filling really good about it.

Anyways, that was my thought process…LOL…hope it helps man, I KNOW in my heart I got lucky…but I’ll call it a win.

 

The diesels have a vacuum pump to operate the cruise and H-vac if I'm not mistaken.

 

My 1999 dodge ram 2500 cruise control just stop working. The light does not even come on, is there a fuse somewhere? Any Ideas.