Where to start - Cruise Control '94 2.3L

[ForgedCrank]

Hi all, been a while since I posted. Life stuff, and my last son just left a few weeks ago for boot camp so I'm not in the best of spirits these days... this getting old thing came up on me faster than I wanted hehe. There are no other remaining targets at home for the wife, so she's eyeballing me now with task lists longer than I care to acknowledge.

ANYway... cruise control. Let me start off by stating, I'm an electrical idiot and troubleshooting anything NOT mechanically pure is a serious weak spot for me. Even wiring diagrams look like Chinese to me, so I'm pretty much flying blind here. I don't even know how the system works.
So here's my symptoms. Cruise has never worked since I got this thing last summer. Best I can tell, there is also no dash indicator light on this model year that indicates when the CC is powered on or activated.
Attempting to activate the CC does nothing. What I have noticed is that lower speed driving around town, I have an occasional glitch where the throttle is sticking. I picked up a replacement throttle cable thinking it was gummed up or something, but I've never swapped it out yet. But then yesterday I started really paying attention. When the "throttle sticks", I can just press the clutch pedal and it releases. This is leading me to believe that this is the cruise control vacuum motor grabbing hold of the throttle for some reason. I'm absolutely positive I am not pressing any of the CC buttons.
Anyway, I've tried one test and that is moving the vac line on the CC vacuum motor and flipping it around and it responds as expected by raising the engine speed when under vac, so I think that part is functioning. I've seen ref to vac operated safeties on the brake and clutch pedal system, but I cannot for the life of me see up in there to look at anything.
So can anyone tell me how to go about troubleshooting this stupid thing? For the short term, I've disco'd the CC cable on the TB so it's INOP and can't cause me grief, but I'd really like to get this thing working... I just don't know where to start and need someone to hold my hand and walk me through it if there is someone with experience on this thing.
Is anyone willing to take this on and assist? I do have the Ford shop manuals for '94

 

[Brain75]

Ok so first I'll ask, this is a factory cruise, not an aftermarket or dealer add on right?

Dealer add on has a bit different clutch and brake setups (separate switches) and the brain box is totally separate and fairly easily identifiable.
(I did a dealer add on to my 2nd generation, but I looked at a lot of 2nd and 3rd gens in the 'yard.)


Factory cruise can be added via junkyard parts in the 3rd gen - the tech writeup is worth a review so you understand all the basic components and where you are looking etc:

Adding Cruise Control To Your Ford Ranger - The Ranger Station

Disclaimer: The Ranger Station.com, The Ranger Station.com Staff, nor the original poster are responsible for you doing this modification to your vehicle. By doing this modification and following this how-to you, the installer, take full responsibility if anything is damaged … Continued

www.therangerstation.com

You shouldn't have to mess with the steering wheel - almost certainly all that is working ok so in reading can kinda gloss over the first bit.

Nothing Ford made in 1st, 2nd, 3rd (I think all the way till end of generation) had an indicator light - so you will be probing around to find out if it's on+standby, on+active (which means having the meter all setup while you go down the road > 25 mph)...


1st thing, check the fuses and make sure they aren't blown.
2nd vac lines - does everything look pretty correct to the shop manual or has someone removed a bunch of lines fix something else (specifically in and around the cruise control servo)?
3rd, under the hood - brake master cylinder has the wiring for the disconnect and your big 10 connector on the fender populated?

 

[ForgedCrank]

Ok so first I'll ask, this is a factory cruise, not an aftermarket or dealer add on right?

Dealer add on has a bit different clutch and brake setups (separate switches) and the brain box is totally separate and fairly easily identifiable.
(I did a dealer add on to my 2nd generation, but I looked at a lot of 2nd and 3rd gens in the 'yard.)


Factory cruise can be added via junkyard parts in the 3rd gen - the tech writeup is worth a review so you understand all the basic components and where you are looking etc:

Adding Cruise Control To Your Ford Ranger - The Ranger Station

Disclaimer: The Ranger Station.com, The Ranger Station.com Staff, nor the original poster are responsible for you doing this modification to your vehicle. By doing this modification and following this how-to you, the installer, take full responsibility if anything is damaged … Continued

www.therangerstation.com

You shouldn't have to mess with the steering wheel - almost certainly all that is working ok so in reading can kinda gloss over the first bit.

Nothing Ford made in 1st, 2nd, 3rd (I think all the way till end of generation) had an indicator light - so you will be probing around to find out if it's on+standby, on+active (which means having the meter all setup while you go down the road > 25 mph)...


1st thing, check the fuses and make sure they aren't blown.
2nd vac lines - does everything look pretty correct to the shop manual or has someone removed a bunch of lines fix something else (specifically in and around the cruise control servo)?
3rd, under the hood - brake master cylinder has the wiring for the disconnect and you big 10 connector on the fender populated?

Howdy. Thanks for the reply. I've been at the data center all freekin day running a rotary hammer and didn't get home til it was already dark. I'm wiped out...
I wouldn't know the diff between a dealer added CC and factory, but I can't imagine this is an addon. It has the std steering wheel controls, and the vac motor thing looks like an OEM part. I have checked every single fuse in the thing already and I used a meter instead of just looking at them.
I tried looking at the vac hoses, but like I was saying, I can't even see up that far under the dash. I know there are supposed to be vac connections to a couple of cutoff valves up there, but I'm unable to locate them. I figured the only way I'm getting in there is to pull the lower dash out and maybe I can see what is going on that way.
I'm going to go through that link you sent before I do anything else. Understanding all of the pieces and what they do will go a long way to helping me figure this out. I appreciate the feedback.... I'll come back again after I check this stuff out and see if I can make any sense of the vacuum diagrams afterwards.

 

[Brain75]

On your todo list if you don't mind... I am working off a 2nd gen example and have all the 2nd gen diagrams in front of me (thank you fellow TRS members), but none of the 3rd. If you would get a copy of the relevant pages so we can help guide you through this with the right docs that would help.

 

[ForgedCrank]

On your todo list if you don't mind... I am working off a 2nd gen example and have all the 2nd gen diagrams in front of me (thank you fellow TRS members), but none of the 3rd. If you would get a copy of the relevant pages so we can help guide you through this with the right docs that would help.

 

[Brain75]

ah yes, factory I forget (I had to do dealer add on)... you must have a functioning horn for this to work as well... so on the initial check would be does the horn work.

 

[bobbywalter]

plug the vac line and test.

 

[ForgedCrank]

On your todo list

 

[ForgedCrank]

plug the vac line and test.

Not sure what you mean? I did do the one test on the servo... you plug it into itself (trying to remember exactly but I think that's how it was done... or I supplied vac from somewhere else. it's been a couple months can't remember now) and see if it reacts, and mine does open the throttle so it is moving.

 

[ForgedCrank]

ah yes, factory I forget (I had to do dealer add on)... you must have a functioning horn for this to work as well... so on the initial check would be does the horn work.

yes, the horn does work

 

[bobbywalter]

the white side vacuum line.

 

[ForgedCrank]

the white side vacuum line.

Ok I'll dig out that other section of the manual tomorrow or the next day and try that. And by plugging it, you mean cut off the vacuum TO the dump valve, right? I just have to figure out where this stupid thing is and what it looks like. All the stuff I'm finding online is for newer systems with electrical disconnects and mine appear to all be vacuum operated

 

[RobbieD]

I do have the Ford shop manuals for '94

ForgedCrank-

I see that you do have the two volume "big book" set (good on you, my friend!). While it does cover everything cruise control related in section 10-03, the big problem with these manuals, is that early on in the diagnostics it falls into the use of having a "Rotunda (Ford) Speed Control Tester 007-00013 or equivalent". I doubt that most Ford dealerships would have such a tool after 31 years, much less a tech that can even work on something this old. But, that shop manual does have the best information for the cruise system, so do refer to it. Rely on the info there, but you have to adapt for the DIY approach.

Having said that, I found the following article on the web that I saved that may be helpful for someone troubleshooting a cruise system with just a meter. Please see the attached .pdf file.

It sounds like you have an "almost working" cruise system. It may just need some "cleaning up", and USE. Stuff which don't get used tends to get temperamental . . . (don't ask . . . ).

For what it's worth, after all this time since new, the clockspring contacts can be a weak point, since the cruise switch inputs are resistance-based. Dirty contacts can throw the seen resistance values out of whack. It's kinda a pain, but pulling the steering wheel and servicing the spring contacts and clockspring tracks would be worth considering. Especially the tracks, bet that you find green crud on them. If you find them cruddy and dirty, clean everything up with contact cleaner, or alcohol, and Scotch pads.

The dump valve is best accessed by removing the knee trim panel and the metal bracing behind it, below the steering column. Only about 4 or 5 7mm screws, if I remember right (no guarantees on that one, though!).

Take a deep breath, and chill. You'll get it. Good luck!

 

[ForgedCrank]

ForgedCrank-

Thanks for the PDF, a lot of it doesn't make sense to me but I'll hack at this over time as I get some free time to dig at it. Even though this is probably considered a pretty simple system by modern standards, it's pretty complicated for my level of understanding. I'm going to have to read through all of this stuff a few times so I can first figure out what the system expects and how it reacts, then I have to figure out what all these parts look like and where they are. The terminology even has me confused... it's gonna take me some time for sure. this thread will prob end up setting a record if you guys stick it out with me hehe

 

[bobbywalter]

if the dump is stuck open you might be able to hear it hissing when idling. if its stuck open its in cut out mode.

from there...sure the slip rings might be corroded...worth a look if for sure the unit has power and ground.