Question about Cruise control and manual transmissions
 

I am going to be installing cruise control on my 2001 Ram 2500 diesel with a 5 speed manual. I am going to install a factory cruise set up. In researching this, I read somwhere that Manual transmission trucks do not use cruise control servos. Is this true? Can someone with a 24V manual transmission and cruise control verify this??

I have worked on literally 1000s of these trucks but I never paid attention to cruise set ups on manual trucks. What I read was the ECM just controls the throttle with inputs from vehicle speed, brakes, and cruise selector buttons.

The ecm controls the cruise and all you should have to do is get a different clock sping and the buttons and it should work. I have cruise on my 6 speed.

Thanks. I will go and try and pick up the parts for this today.

---AutoMerged DoublePost---

So I picked up a complete new column from the wrecking yard today. They would not just sell me the clock spring and switches but for 80 dollars it was not too bad for the entire column. I may find a way to install the column as I do not have a tilt column and this one is tilt. The only down side is it is an automatic column and I have a 5 speed. I will have to see if I can remove the linkage for the shifter. I know I can remove the shift lever easy enough just would like to get rid of the the rest of the stuff as well. I will keep you posted.
:pca1:

Actually the PCM directly controls the ECM fly by wire means. Yes its true that the manual trans truck do not have a vacuum motor for pulling the throttle cable. I find that manual cruise control is very stable and less likely to the jerky reactions like auto's with vacuum motors.

I wish I had a wiring diagram of it... But as far as I've learned the PCM has a set of APPS leads tied to the ECM.

I hooked up the switches and clock spring.. I still have no cruise control. Does anyone know if there is a way to tell the ecm that it has Cruise. All the diagnostics I can find are for automatic equipped trucks with the cruise servo. If I can not get it to go with out the servo, can I install the servo. The plug is there under the drivers battery.

Well the thing to check is see if the old wheel has all the connections/wiring for cruise. I've been told and read thats all you need. Does your cruise light come on the dash when you turn the button on the wheel? When you turn the key on I think it should pop up since that is like a bulb test.

It does not come on for a bulb test or when you press the buttons on the cruise. I did test drive it and attempted to engage the speed control thinking maybe it is just missing a light. Still no cruise. The clock spring connector does have all the wires to it.

I pulled codes from ECM and PCM with my Snap On scanner. No codes in ECM except the code for trouble code in companion module. PCM had code for speed control solenoid circuit. I didnt write down the P codes. There is no check engine light and the PCM did not have any codes before I started this project.

I am going to check the voltage at the speed control switches tomarrow. According to my diagram. It should come from Pin 22 of the ECM and go through a series of connectors to wind up at Pin 1 or the clockspring. It is supposed to be a red and light green wire. The fact that it sent the single to the PCM makes me think that perhaps the truck is wired differently than a factory cruise truck would be. It may be as simple as connecting that circuit to the right connector in the ecm.

---AutoMerged DoublePost---

Or another thought is I may have to go and get by my old work and see if they will hook up a DRB to it and may have to manually turn the option on.

Well I'm not real sure but I don't think there were different options when it came to pcms. You either had auto or manual. I started to read the 01 fsm but ran out of time 3:30am here. I do know the PCM sends power to a wire to turn the cruise light on. Maybe the PCM isn't getting a signal that the cruise is on.

My cruise on/off button has to be pushed very hard to come on and theres a little light on the button that lights up when it's on. Not sure if a 24 valve even has the same buttons as a 12 valve but worth trying I guess. :c:

Nope they are different than the 24vs

I am thinking i may have to just come up with a drb to tell it that it has cruise now.

Any other suggestions on how to get the cruise control to work? I have installed factory switches. Checked voltage at the switches. Switches are working. No light on Dash board. I even installed a cruise servo off of my wifes truck and still no cruise. Any Ideas? I am all ears.

Well I think if you find out why your cruise light isnt coming on you will find out why you dont have cruise. Bad switches maybe?

The truck has 5 volts at the cruise switch connectors. When you back probe the clock spring connector and press the button it changes voltages. That tells me that the cruise switches are working.

---AutoMerged DoublePost---

The wiring diagram I have does not match the truck. My diagram says a red and green wire comes from the clock spring down through C130 then splits and one leg goes to the PCM at pin 32. The other leg goes to C126 on pin 2 then down to Pin 22 of the ECM.

On my truck Pin 32 of the PCM is a red and green wire. On my truck Pin 22 of the ECM is a red and green wire. Connector C130 has the red and green wire on pin 41. C126 has the red and green wire that goes to the ECM. On the other side of the connector it has a black and tan wire that disappears into the harness. There is no continuity between the wire that leads to the ECM and the wire that goes to the PCM. The only difference it shows between a manual and Automatic transmission is a splice on the ground wire side.

I still have no cruise control but I did find something interesting today.

I was at the parts store this morning and a guy drove up in a 2001 Dodge Ram 2500 4x4 5 speed manual. I got to talking to him and asked if he had cruise control. He has factory cruise. We went and opened the hood and he has cruise servo under the drivers battery. So some did have the cruise servo with a 5 speed. I wonder if I should chase this direction more?

Any ideas?

Maybe? I know I had my batts and trays out back in aug and I dont have one. My 02 with factory cruise. Ill look to see what all I can find on my truck. Look on your door and see what your build date was.

I wonder if it was a change over year in 2001 to 2002. I know that sometimes the books jump the gun in regards to what actually comes on the truck. I dont remember the date but seem to remember my truck being built in mid to late 2000.

Yeah thats what I was thinkin. I know that 02 trucks arent supposed to have central axle disconnect(cad) but mine does because it was built in nov 01

Still haven't gotten the cruise servo yet but was at the Dodge dealership today where I used to work and they let me rome the back lot looking at the trucks that were in for repairs. I found 2 2000ish 24 valve 5 speed trucks on the light. 1 2wd and 1 4wd. Both had cruise servos. If I get a chance to get to a junk yard, I will be picking me up one to try it out.

my cruise is great on my 6 speed but with all my mods it takes off like a bat out a hell and leaves a huge cloud behind me. It surges pretty bad but when it was stock cruise was very stable!!

does your truck have a cruise servo? The discussion included weather or not manual transmission 24 valve diesel trucks use a cruise servo or just the programming in the ecm?

Wiring Diagrams...?
 

Condor74, you mention a wiring diagram! My manuals only show the wiring for servo-based speed control but I, like you, have a manual transmission. Could you, or anyone else, post this wiring diagram?

Auto's&5 spd's have the servo, 6 spd's do not,this is according to my factory service manual

That's good info. Another thing to look at is the throttle control. The older TPS systems require a servo while the newer APPS systems can run from the ECM.