cruise control issues

[AKBroncoII]

My cruise control doesn't work. How do I diagnose? Obviously I can't leave the hood up and hang out the window going down the road. Should I replace the vacuum canister deal? It's a manual transmission truck, how do I test the VSS?

 

[85_Ranger4x4]

What year? A BII shouldn't have a VSS.

On my parents '94 Explorer you have to pull the brake pedel up just a little bit for the cruise to work, after 180k it doesn't always get quite all the way back to where it is supposed to be, my dad's '92 GMC does the same thing.

 

[shadetree]

I would start by check all the vacuum hoses. Also, the brake valve as suggested.shady

 

[Jorley]

How is it not working? Pick a number.

Problems:
1. Will not hold proper speed
2. Cruise intermittently cuts out
3. Vehicle surges
4. Cruise control inoperative

Possible causes:
1. Incorrect cable adjustment; Binding throttle linkage; Leaking vacuum servo diaphragm; Leaking vacuum tank; Faulty vacuum or vent valve; Faulty stepper motor; Faulty transducer; Faulty speed sensor; Faulty cruise control module

2. Clutch or brake switch adjustment too tight; Short or open in the cruise control circuit; Faulty transducer; Faulty cruise control module

3. Kinked speedometer cable or casing; Binding throttle linkage; Faulty speed sensor; Faulty cruise control module

4. Blown fuse; Short or open in the cruise control circuit; Faulty brake or clutch switch; Leaking vacuum circuit; Faulty cruise control switch; Faulty stepper motor; Faulty transducer; Faulty speed sensor; Faulty cruise control module

That's the cruise control troubleshooting chart from my 83-90 Chilton's manual. Hope it helps.:icon_thumby:

 

[Wicked_Sludge]

What year? A BII shouldn't have a VSS.

pretty sure if its got cruise, its got a VSS....

 

[AKBroncoII]

It doesn't do anything. Doesn't work at all. Nothing happens. It's a 91 explorer.

 

[Earl43P]

Does it have a pressure switch on the brake master cylinder? If so, remove its connector and jumper the two pins. That'll rule out one thing pretty quick.

Manual trans will also have a clutch pedal switch that disengages the Cruise at the first bit of clutch pedal movement, unlike the contacts which allow starter engagement, which "make" at the end of pedal travel (bottom).

 

[AKBroncoII]

It is a manual transmission. The clutch pedal does seam like it is down further than it should be.

 

[Earl43P]

On my 2000, it takes just the lightest tap on the clutch pedal to kill the Cruise.

If yours isn't fully up, that would certainly do it.

 

[AKBroncoII]

What would cause it to not come up fully?

 

[Jorley]

The troubleshooting chart I posted is for 83-90 Ranger/Bronco ll, but should give an idea on what to check. Check all the items in step 4.

Here's some wiring diagrams for the cruise control.
http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Cruisecontrol_1of2.JPG
http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Cruisecontrol_2of2.JPG

 

[Earl43P]

Slave or Master or it could simply need bled.

I'd drive it, lift the pedal fully up with my toe and see if Cruise will engage.

 

[AKBroncoII]

It's sloppy, as in no pressure or anything to hold it up. It's not the slave. Could be the master as it is the only thing that has more than 500 miles on it. Clutch, pressure plate, flywheel and master are all brand new. It was the same with the old stuff in also. The pedal will fall back down anyways. Do you suggest I just hold it up with my foot? Couldn't I just test continuity through the switch with it where it's at?

 

[AKBroncoII]

Looks like it is the clutch switch. Works when I pull up on the clutch pedal. Now I just need to figure out how to fix it.

 

[Wicked_Sludge]

check all the clutch pedal bushings.

 

[AKBroncoII]

Will do. I will check those.

 

[nnehrer]

Cruise control doesn't work.

Cruise control does not engage.

Blown fuse; Which fuse is for the cruise control? Does this fuse control anything else?
Short or open in the cruise control circuit; How can I check this?
Faulty brake or clutch switch; Checked switch seems to be ok. Master cylinder has been replaced. I saw it mentioned that the Speed Control Deactivation Switch, also known as a "brake pressure" switch is located under the hood of the vehicle and is attached to the brake master cylinder on one end and wired to the cruise control on the other. I don't know if this applies to my model. There is a connector plugged into the master cylinder.


There is a plug coming out of the wire harness that is plugged into the master cylinder but nothing is plugged into the end. I'm not sure if anything is supposed to plug in there.

http://www.flickr.com/photos/14548977@N08/3888244158/

Leaking vacuum circuit; Vacuum plugs seem good. Am I missing some? There is what seems to be a vacuum hose running along the firewall but doesn't go into anything. I checked a similar model ranger and it goes back into the firewall but mine just seems to be snipped off. There isn't a place on the firewall that it looks like it could attach to.

http://www.flickr.com/photos/14548977@N08/3887450603/

Faulty cruise control switch; Not sure, I check the switches on the steering wheel and they look in good condition. The horn works.
Faulty stepper motor; Not sure where this is
Faulty transducer; Not sure where this is
Faulty speed sensor; Not sure where this is
Faulty cruise control module; Not sure where this is

Hope this isn't too much detail but I'd like to get this fixed it's been bugging me for awhile. Thanks for any help you can give.

I have pics if necessary but I couldn't attach them without linking them from a website.

 

[Kalwren]

I'm curious how this is going to turn out. This is the next project that I plan to work on with my truck. My cruise isn't working either. This thread gave me some great things to check though.

However, what - and where is the transducer?

 

[fastpakr]

Unless I'm losing my mind, the transducer is also called the 'cruise amp'. That's mounted above the glove compartment. Just drop the compartment down and look behind/above it and you should find the module tucked up there with two wiring connectors (each with 8 or so wires). It's a green plastic unit on my '94 Explorer.

 

[Kalwren]

Good info, thank you. I was able to locate the the transducer where you said it was.

I pulled in the tabs on my glove box and was able to swing it down into the fully open position and look up under the dash. The module is green and has a wiring harness connected to it on the right side.

The interesting thing is, the next thing I was going to work on was the "blend door fix". Turns out, my antenna cable was pushing against the rod that operates the blend door via the vaccuum switch. I moved the cable and now it opens and closes fully. I expect my AC to be much colder now.

I don't mean to hijack a thread though. Sorry.