Hey all, from Southern Illinois!

[zekew64]

Hey e'erybody! My name is Isaiah; I've owned a '92 Ford Ranger for about 2 years now; been thinking lately about the custom engine I want to build...going to take many papers with dead presidents to make that happen, lol!

Hope all goes well here...I'm also on therangerstation.com, and fordrangerforum.com as well.

By the way, got a question for y'all out there.

When I replaced my 2.3L I4, and put everything back together, I hooked up my cruise control. The issue is that when I started my truck, it would act like it was at WOT; needless to say, it would rev higher and higher, without settling on a level RPM. I've disconnected it because of it, but I would like to be able to drive long distance and not have to have my foot on the gas constantly.

I do know that the vacuum hoses are good, along with the servo. I confirm this by disconnecting the actuator cable (connects to the TB), and when I started my truck, the servo had pulled the actuator cable tight, like it would have kept the throttle at wide-open.

Now, having said that, what would cause the system to act like this? The brake lights work, so I know it's not the brake switch. The only things I can think of that would be bad are:

1) Cruise Control Transducer
2) Cruise Control Amplifier
3) Bad Cruise Control ground? Where is it located? Motorcraft.com says that there is a ground wire.
4) Bad Cruise Control Inhibitor Solenoid, if it has one?

How do I track down the cause? I know that the rest of the vacuum lines are good, that the EGR and TPS works. I've also got mechanical skills, and fairly decent electrical skills; I know how to use a multimeter. I just don't know where to start, testing what components. Also, I don't know if it is relevant, but I had to take out my RABS fuse, as I think I've got a bad sensor in the differential (I only have rear ABS); I don't know if the cruise control would be tied to that system or not.

Thanks for all your guys' help in advance!

 

[BrooklynBay]

Welcome to this forum! Check the owner's manual to see if both systems are on the same line. A schematic diagram will show you everything.

 

[zekew64]

No such luck, lol....the only thing I can tell is that, according to the interior fuse panel, there is a speed control amplifier and a speed control inhibitor. On the inhibitor side of things, the other circuits are my stop (I'm assuming brake lights) lamps and 4-way hazards. I know my brake lights work; the question is, where does the wiring for the inhibitor go? What components and grounds are included? I wish I had the information for this gremlin...

 

[FR-425]

Cruise Control

Hey Isaiah,

Here is the whole Ford trouble shoot Guide for first gen cruise control.

Had to pull it from several different images so it's all broken up and not in order. I put the word "space" between each image. Should be able to save so you can print ,enlarge ,whatever.

space

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[zekew64]

Thanks for the info. However, I have a couple of questions:

1. On motorcraft.com, I see the option of dealer-installed vs. factory-installed speed control. How do I tell the difference?
2. On the troubleshooting charts, I keep seeing this term: the vacuum dump valve. What is it, and where is it located?
3. I also see tests that don't apply to my Ranger, in that it references to buttons on the steering wheel; I don't have those. Rather, I have a control stick, on the right side of the steering column, that uses a control stick similar to Ford's multifunction switch, for the wipers/turn signals/wiper motor/bright lights. It doesn't move up or down, only it twists back and forth to control the cruise system (On/Off, Resume, Accel functions).
4. Also, I don't know if this is relevant, but I have a 4-pin vacuum servo vs. a 6-pin servo. Does this make a difference? Or, as I'm thinking, determine whether the system I have is dealer-installed or not? How do you tell the difference?

Also, FR-425, one of your images are missing, as it didn't load. And, since I haven't done it yet, thank you for uploading these diagrams. Hopefully, I can get my cruise fixed and not have to keep my foot on the gas on long trips. Thanks for everything.

 

[FR-425]

Whoops that was the good pic too!
It's now the last one.

The vacuum dump valve is attached to the brake pedal along with the brake light switch not all will have this. This also answers your other question, if you do not have the dump valve it's a factory install, if its there its dealer install. The ones installed after shipping need this extra feedback to kill the cruise when brake is applied because the wiring and dump are missing. the factory one's just blow off at the actuator and is not serviceable you just have to replace the servo.

If it is bad the servo won't hold vacuum.

For the control stick trouble shoot the same way. They are just switches.
remove it and test with ohm meter to see if you get continuity when you rotate the switch to the various positions.

These diagrams are for Explorers so the color codes may be different. but it is likely they are the same. If not, after poke'n around you'll figure out the differences.

start with the simple stuff. this guide is in no particular order. so just skip those that do not apply. You'll find the problem before it gets to deep it's usually the mechnicals that are screwy not the electrics.

If you or somebody else has wired up trailer lights make sure its right or it will send a brake on signal and keep the cruise in off mode because it "thinks" your foot is on the brake.

 

[FR-425]

I had a similar situation on my 94 Ex Limited.

With the towing package there is a set of relays in the rear quarter.
these prevent the new load from the trailer lights from making your flashers blink to fast. Like an after market trailer load controller only built in. Sweat! Until your cruise quits!

So it took me a while and some research some do here on this site.

This is why I have the bloody diagrams.

Any how my problem was intermittent what a PITA. but I eventually narrowed it down. loose relay pulled it out cleaned reinsert whala!

Don't get frustrated spend a little time on it then quit.
A little down time for the brain and things sometimes seam to fix themselves.

 

[zekew64]

Okay...thanks for the info, and the reloaded pic.

I noticed, underneath my dash, that I have what I believe to be a dump valve attached to the clutch pedal, not the brake pedal (there is a vacuum line with a plastic, spring-loaded valve). I have the Mazda 4-speed w/OD as a transmission, ergo, I have a stick shift.

As to the question of whether the servo holds vacuum, it does; that isn't the issue. What is the issue is there is no control with the servo/actuator cable hooked up; when it is, the RPMs on the engine just keep rising--and that's at idle. It doesn't want to idle properly. It's almost like the cruise is constantly trying to engage, whether it is in gear or not.

I also noticed that I have an inhibitor solenoid that is wired up with my hazard flashers and brake lights. Where on my truck would the inhibitor solenoid be? I've been told, and researched it, and it leads me to believe that it is underneath the driver's side headlight assembly. I've looked under there, and there is, in fact, something that looks like the vacuum servo, only it's smaller and it looks to be yellow in color. However, I've not followed the wiring to see if it is on the same circuit/harness that the vacuum servo is on.

 

[zekew64]

After doing A LOT of research, and taking into account one repair I made, there are only 2 components that could be bad; one is the switch itself, and the other being the amplifier control module.

I do recall, before I replaced the motor in my truck, that I turned the system on, to see if it worked; it didn't, due to vacuum lines being melted in two (still don't know how that happened! lol). My problems only happened after I replaced those lines, and cleaned up the EGR (cleaned most of the caked-in carbon out of the pintle area).

Thus, I'm going to test the amplifier control module and the switch to see if either one is bad, or if there is a short to ground anywhere. Other than that, I'm not sure what else the problem could be.

 

[FR-425]

Can you actually see the cruise actuator pulling the throttle when it's just sitting at idle?

I was thinking automatic trans. so yes the dump on the clutch makes sense.

 

[zekew64]

Actually, I found the dump valve on the brake pedal; I went out and examined the system the other day. So yes, it is located on the brake pedal.

And yes, I did see the actuator cable pulled tight. What I did was I hooked everything up, including the vacuum portion, and started the truck. But what I did NOT do was hook up the actuator cable to the throttle body, so that it would not rev so high that the engine would have been damaged. And, what I saw was that the cable was pulled all the way in.

What I'm thinking is that I have a faulty inhibitor circuit. The inhibitor circuit, IMO, is either controlled by the switch, by the amplifier module, or there is a short-to-ground somewhere, in that the inhibitor circuit can't function, electrically, to inhibit the system at all.

Also, one thing I did repair on my truck was the vacuum lines that run along the firewall to the vacuum switch on the passenger side. Before I discovered these lines melted in two, I had attempted to switch on the cruise system to see if it worked. I'm thinking that the switch might have been corroded enough to where the switch could not have turned off the system. I do know that the bulb works, and that it doesn't come on when I start my truck. But the bulb might be burned out; I don't know.

If I can get some warmer weather, I plan on testing the system, at the amplifier module, to see if it's bad. I did do a continuity test on the vacuum servo; it checked out, in that all the pins had continuity. So, I know that the servo more than likely works. I also know that the inhibitor fuse works, as my brake lights are part of that fuse, located under the dash, and they work. The brake switch also works, the horn works. At this point, I'm not sure what component is bad; I'm assuming that it is an electrical component, as the vacuum lines aren't leaking and aren't dry-rotted or cracked. I also know that the EGR system works, as I had to clean the valve (it had so much carbon in it that the pintle wouldn't move under vacuum) before I installed it on my truck.

Having said all that, I'm not sure what would cause my truck, even at idle, to rev that high. However, FR-425, I don't know if I hooked up the system correctly. I have the following components: A vacuum reservior (One inlet, one outlet for vacuum), a vacuum servo (also one inlet, one outlet for vacuum), the dump valve. How do I hook up the system correctly, to make sure that the system, at least on one side of the control equation, is correct?

Note: I think, after looking at everything, that I might have hooked up the system at the servo backwards. I recall that I hooked up the vacuum hose from the vacuum tree into the port of the servo that the dump valve is supposed to go to, thus bypassing the control solenoids on the inside of the servo. I don't have the 6-pin servo; rather, I have a 4-pin servo. With one connector on the servo, I can push the diaphragm and get a small thrust of air. It is this port, I believe, is supposed to be hooked up to the vacuum dump valve. I got this information from the following website:

http://www.thorssell.net/hbook/ccwire.html

Hope this site helps other people like it did me. I'll hook up the system tomorrow and see what happens, and then post the results on here.

 

[zekew64]

Well, re-hooked up the cruise control. Would not turn on, electrically-speaking; so have to chase gremlins and replace bad wiring/components, I guess.

On the plus-side, the truck didn't rev up like it did when I put everything together last August. So, yes, I can honestly say that I hooked it up backwards (d'oh!)

Also, after doing some problem-solving, I figured out that the inhibitor circuit is controlled by the rotary switch on the steering column. So, no seperate "inhibitor solenoid" to speak of. Thanks again, Fr-425; the diagrams and testing flowcharts were (and will be) a big help.

 

[FR-425]

It makes sense that on a standard trans there would be a dump or at least an electric switch on both clutch and brake so either way the cruise is killed.

Also cruise cannot be engaged until the vehicle exceeds 35mph so static testing for power up is not going to prove anything out.

Switching the knob to on position won't do anything with the vehicle sitting still.

That's what the inhibitor circuit is all about, to prevent setting cruise at to low a speed or when in neutral etc.

In other words there will be no power at the switch until 35mph.

You can do all the "continuity" checks in the driveway but functionality can only be done while at speed.

One reason these can be such a PITA to trouble shoot.