Please help with my cruise control

[tweakedlogic]

I am leaving for a long 850 mile trip today. I have been trying to get my cruise control to work for months now. A brief history: last year i bought a body with a blown motor for cheap. I installed my motor, as well as a few other things. In my old body the cruise control worked. In this body i have switched over the steering wheel, cruise control module, and the unit under the hood.
I have no blown fuses, and no vacuum leaks.

I am at wits end. The only thing I haven't swapped is the body wire harness. I followed the wires from the actuator through the fire wall to the main harness, and I don't see any damage. There doesn't appear to be any damage to the wire @ the control module either. The vacuum switch on the brake pedal also tested good. the previous owner did bypass the clutch pedal switch. Could that have anything to do with it? There are also a few other wires he spliced into under the dash, but I'm fairly certain they are not associated with the cruise, I may be wrong though.

I don't know how (or what) to test. Can somebody help me? What wires are supposed to have power when the module is On? Is there a sensor somewhere I should check?

My truck is a 92 4x4 4 door XLT 5 speed.

 

[Baddecision93]

I could be wrong but I thought these had a recall for cruise control modules...have you had that done?

If I'm not mistaken it fixes a wiring problem that can result in overload and fire. It might be worth a call to the dealer to verify. If that's the case perhaps yours just overloaded to the point of losing function but not to the point of catching fire.

Just an idea.

 

[tweakedlogic]

Hummmm, I didn't know of any recall. however, I did swap over everything from my old truck except the wiring. Cruise worked in my old truck. The recall was probably done on my old truck. A friend's dad bought it new and maintained it meticulously. I would have kept that body had it not been for the ass hole with no insurance that can't look before crossing traffic.

Edit: On thing i just thought of is the PO cut up all the wires for the radio. I think the cruise and radio are on the same fuse. Is it possible that some of the wires he cut back there need to be hooked up?

 

[Joe Dirt]

The recall was for the brake switch.

The clutch bypass might have something to do with it... Did you check the wiring?

 

[tweakedlogic]

The recall was for the brake switch.

The clutch bypass might have something to do with it... Did you check the wiring?

It looks like the clutch switch failed and he cut the two red wires and crimped them together. It's a solid connection. I think if it were done wrong the starter wouldn't engage.

 

[Joe Dirt]

Yep. Eliminates that.

Are you sure the cruise control unit itself is good?

 

[tweakedlogic]

Yep. Eliminates that.

Are you sure the cruise control unit itself is good?

Well, I know it worked a couple of days before I did the swap because i pulled the new explorer with my old one on a trailer for 180 miles. I used the cruise after i got out of the hills.

how would I test it?

 

[Joe Dirt]

Unfortunately, I have no idea...

But, maybe the factory service manual has a procedure in it, possibly someone can look it up? I'd do it, but I'm leaving from work to head north so I can't be of much help there. :/

Any chance of a junkyard close by to pull a unit and try a different one?

 

[tweakedlogic]

Well, before I left Friday I checked every connection (even under the steering wheel cover), I blew and sucked in every hose, and the brake switch. So I got on the road and tried the cruise, It worked, well sort of.
It seems to over correct constantly. It will floor it and then decelerate over and over again. It's almost enough to give you motion sickness. I was able to make it a little better by holding my foot on the pedal so it wouldn't decell as much. But mostly I just didn't use it.
Any ideas what this is about? Should I change the actuator?

 

[Roadrunner777]

I had this over-correction when I first got my cc working. It worked itself out, but I might think about checking the cable from the actuator to the TB for binding.

 

[tweakedlogic]

Thanks roadrunner.
BTW, what is the cruise control dump valve tip?

 

[Roadrunner777]

When I started diagnosing stuff, the CC wouldn't engage. I read here in a quick search to check to see if the dump valve was closing. I reached up from the brake pedal, found the switch, moved it around a little bit, and it has functioned quite well, again, once I got past the over-correction. That didn't take more than a month, I guess before the over-correction worked itself out.

Then there's the bit about cc and the 3rd brake light, I guess you read about that already. If the 3rd brake light burns out, cc won't work.

 

[tweakedlogic]

Okay. I did check the dump valve. I posted it earlier. I physically removed it, sucked through the port and cycled the button to see that it was sealing well and venting properly.
I'll check the cable from the actuator tomorrow. I don't like the surging. It seems like it will use more gas that way, and I really don't like the feeling. I may go ahead and replace the actuator if it doesn't work it's self out soon. I'll try to remember to use it every time I go somewhere.

 

[Joe Dirt]

Now that I'm back in civilization, I apologize for my absence... You're on the right track though. I had to mess with the cable to cure surging on my '95...