New to the posting part of this forum although yalls threads have helped me drastically over the last few years. I have a 1993 ext cab le that was a 518 then a 47rh and now a temporary getrag until my nv4500 slides in its place. I have not been able to get my cruise control to work whatsoever. Ive gone through all the usual steps ie. Voltage where it should be checked function of clock spring. Everything is getting power and functioning correctly but still no cruise. I have a potentiometer in place of tps to show computer that voltage is there but im assuming its not working due to the plug for overdrive just hanging out not doing anything. Any help would be greatly appreciated. Thanks in advance.

 

Cruise control has nothing whatever to do with OD. It does, however, need a good signal from the VSS. If your speedometer works, the VSS is working.

Whether or not the signal is getting to the PCM is the question.

Another item for Cruise is brake and clutch switch input. That may be the kink.

 

Thank you for your reply. VSS is working properly. As far as clutch switch I have it bypasses so I dont even have to push clutch in to start. Neutral safety switch is grounded as I understand to be common with this swap

 

Without looking at the diagrams, I don't know for sure how it's set up. On the brake pedal switch, there's a second set of contacts for Cruise.

Cruise control is supposed to drop out when you hit the brakes, or the clutch. I think that may be where your problem is.

There's a link to a complete set of diagrams out of the FSM in the stickies.

 

I'm gonna reconnect the clutch safety switch and see if thats where my problem is. Thank you so much for your input. I'll let you know how it turns out.

 

I reconnected the clutch safety switch and still nothing. This thing has me baffled

 

Has anyone out there been able to get their cruise to work after an auto to manual swap

 

You're going to have to print out the diagrams, and trace everything through. So far all I've seen is going by wild undocumented guesses.

There are 3 pairs of contacts on the brake switch for a vehicle with speed control, and only 2 on a non speed control switch. If the wrong switch has been installed, it will not work.

On the diagrams,
Clutch (Park Neutral Position Switch) goes to the PCM on page 8W-52 (AD21)
....detail is on page 7. It's tricky, but the clutch pedal position switch send a signal to that pin on the Pcm when depressed. That can be traced out and tested.

The brake switch has 2 circuits that affect the cruise. Both must work for Cruise to work. Most of the cruise control wiring is on pages 8W-78 and 79.

VSS signal had to get to the PCM
Power on cruise has to get to the PCM
Brake switch good has to get to the PCM
Steering wheel switches have to get to the PCM

Now I've spent a considerable amount of time digging all this out for you. You have to go get the diagrams out of the FAQ's and do the grunt work, or hire someone to do it.

 

How did you handle the neutral safety circuit ground???

 

The truck was cruise to begin with. I haven't added anything other than take it from a fully functioning auto to a standard with no cruise now. The voltage regulator in the ecm is going out and I have been trying to source a new one but other than it should be working. I cannot find the faqs section and for some reason its not letting me fill out my sig so yall know more about what ive got.

 

My speedo also just started doing it the jumping all over thing. I know my vss is good and circuit is good. Im pretty sure my failing ecm is to blame. Hopefully I can scrounge up another one and that will fix it.

 

When I did my 2wd to 4wd conversion on my crewcab my donor truck was a 1993 Cummins/auto. My crewcab was a cummins/NV4500. I used everything from the 93 in my swap, but kept it a 5spd.

My cruise functions...but has some bugs I have not been able to work out yet. But the reason your cruise is not working is because, as Mr. Martin stated, the ground signal to the PCM is incorrect.

So I am assuming you never changed the original 93 Auto wiring? Do you have reverse lights working? If not then you need to look under the truck and find the round black plug with three wires going to is. This was to the Neutral safety/reverse light switch.

Now the two outer wires are for the reverse light switch. The middle wire...brown I believe, needs to be run up to the clutch pedal switch. This wire needs to go to ground only when the clutch pedal is depressed....and a open circuit the rest of the time. My donor obviously did not have a OEM clutch switch, so I made one out of an old brake light switch and wired it up.

The PCM needs to only see ground when the truck is being started, if it sees ground at any other time it thinks the truck is in park or neutral and will not allow the cruise to function.

Hope this helps.

 

Did you get the cruise working?

 

I resolved the bouncy speedo for now by taking it all out and apart and thoroughly cleaning it. Hooked up the neutral safety switch to the clutch safety switch and took him for a test drive. Cruise worked for like 2 seconds then quit again. Checked connections and fuses and all are good. Now the voltage is holding steady at 13 volts. Some little gremlins are giving me a run for my money.