Hi all,
I have a 98 E350 with the V10 and automatic, set up as a handicap van.
Cruise worked fine when I got it, then last fall at the begin of a 1500 mile trip it stopped working right. It would set and hold speed a little while, then disengage. Kept getting worse until it would only hold a few seconds as it does now. After leaving it off for a few hours while driving on the highway, I could turn it on and it would set and hold speed briefly once again.

I read a ton of forum posts but haven't found anybody with this behavior, usually it just doesn't work at all which isn't my case.
Observations:
- When it disengages I hear a loud click like a relay, coming from somewhere below the instrument cluster.
- The airbag light flashes and has done that even when the cruise was working fine.
- Horn always works fine.
- Obviously the buttons on the steering wheel work fine.

Checked the following:
- cruise brake switch, the red one, jumpered the plug, no change.
- followed the procedure with a multimeter on the servo plug, everything checks out fine, except couldn't check the speed signal.
- Speed sensor seems to work since the speedo works fine, as I understand it.
- Horn works fine, checked horn again after cruise disengaged, still worked fine
- Picked up a used cruise servo and swapped it out, exact same part number, no change.

Can somebody help me out, I'm running out of ideas.
Thanks
-Hans

 

Hi Hans,
check to see if the recall has been done and that the switch in question is working. LOTS of vehicles in this recall:
Ford Cruise Control Recall
jim

 

Yes I saw that recall earlier and I thought mine was excluded but now I see it is in the updates, thank you for that link. I didn't see any sign f it having been done on the van.
The van has an auxiliary steering pump to run the steering in case the engine stalled, and that is in the way of all this. First I need to get some flare fittings and bypass the pump out so there is room for them to do the update.
All that said, I don't think that is part of my cruise problem since the test procedure on the cruise module plug came through with flying colors on the brake switch...
I've been reading all I can and it seems the system consists of the switches on the steering wheel and the clock spring inside, then the foot switches inside, and the cruise servo module out in the engine bay. Is there anything else to it? I can't figure out what is the prominent click I hear in the lower dash when the cruise disengages. That seems to be at the heart of the matter.

 

Jim IIRC the E-Series didn't receive the secondary cruise control cancel switch mounted on the master cylinder until 2003 or so. My 2000 doesn't have that feature where my 2003 does. Before I fixed mine it did mimic Hans's situation. My guess is most likely his doesn't have that (#&@& part installed on his '98.

-Speed signal is generated only when the vehicle is moving---can't really test it otherwise.

-Servo's especially pre-2000 are VERY year sensitive---unless the swapped in part is from the exact same year it might not work or exhibit the same issues as with the original part. You do mention the new part having the same part number but confirm it was from (and operation properly) in the same year van as yours.

The intermittent operation suggests a wiring issue, most likely a loose connection at one of the connectors in the entire circuit. This could also be a chaffed wire making temporary contact and shorting the circuit but not blowing any fuses.

The clicking you hear eludes me---there's nothing inside the cabin related to the Vehicle Speed Control (aka "cruise control" in Ford's) to make that sound. The VSC cancel switch makes a clicking noise that's barely audible when it makes or breaks contact, more from the tang touching the brake pedal arm than the switch contacts.

You might double check that inside canceling switch to make sure it has the correct amount of play between it and the brake pedal arm. Mine is self-set so closely a huge bump when VSC is engage will bounce the brake pedal just enough to cancel VSC.

Apart from the intermittent problem your VSC sounds to be working as designed. BTW great diagnostic steps for the steering wheel switches!

HTH

 

JWA, was hoping you would post, you always have good info!
As far as I can see, mine does have the cruise cancel switch on the master cylinder. It seems to be exactly upside down compared to the F-series photos I have seen; there is a black switch pointing to vehicle left and a red one pointing down, near the end of the cylinder.
I took the brown plug off the red switch and installed a jumper in the plug, didn't make any difference.


[QUOTE=JWA;16227232]Jim IIRC the E-Series didn't receive the secondary cruise control cancel switch mounted on the master cylinder until 2003 or so. My 2000 doesn't have that feature where my 2003 does. Before I fixed mine it did mimic Hans's situation. My guess is most likely his doesn't have that (#&@& part installed on his '98.

 

I thought I had read that the same speed signal runs the speedometer?
The cruise does set and hold speed briefly, so I had discounted the speed signal as being a problem

It was from I think a 2000 and unknown operation. The part number had the same "AB" suffix on the part number and I saw another with a "BA" suffix. I figured at least they used the same servo for a few years.
My thought was exhibiting the same behavior meant it probably was NOT the problem...

I was hoping there was a relay under there, something like that, but I see also that's not the case. There is a bunch of stuff crappy-installed like extra lights and a cheap alarm, plus all the handicap stuff. I get the feeling I'm wasting everyone's time here and you're right, a loose connection or chafed wire shorting it out. I will pursue that angle. Just thinking back to before the trouble started, I installed a new stereo, and removed a temporary seat that causes an alarm to sound because it thinks a wheelchair is not latched.
However, the decline in cruise operation was gradual, at first it worked for hours, then maybe an hour, then less and less.

I did think of that, but the van can be running as smooth as can be when it happens, nothing in general conditions seems to have any effect.

Thank you! I wouldn't say intermittent, the VSC operation is very predictable and brief!
One great thing about it being a handicap van is it still has the hand controls. I got so used to using the hand control for throttle, at one point after driving for hours on flat highway I thought the cruise was working again. Then realized my hand was holding the throttle.

 

I'm not following you here Hans---are there two switches on the master cylinder, each with their own wiring harness and connector? Any photos of these on the master cylinder?

By no means are you wasting anyone's time here Hans---please don't think that even for a second. So far you've done a lot of preliminary work others don't do---they simple ask "cruise don't work---why?" or something to that sad effect and expect an instant answer completely fixing the problem for them.

Definitely check any wiring added for alarms etc---poor connections that fail or sloppy installation can lead to problems.

As you've included this condition has been slowly coming on before becoming more frequent it strikes me the servo could be at fault even though we've supposedly ruled it out. Because it will engage says the wiring and switches are good, assuming of course there's no issues with that part of the VSC system.

Its possible the replacement servo is also at fault----that vintage of a part could have any number of unknown issues.

I'm also thinking could the cable from the servo running to the throttle linkage be at fault? I can't think how it would cause the sudden disengagement however that's the only other part not yet investigated so far.

I hope I'm not leading you in all the wrong directions-----I've never encountered a problem like this not somewhat easily diagnosed as we've already put forth.

Geesh I'm stumped at this point too.

 

Hans, the setup for hand controls would mean the original Ford system was modified with inputs from the hand controls? Is there a chance that the relay click you hear is part of the added system for hand controls? It may not be possible to completely troubleshoot the system without knowing what items were added for the conversion.

You should know by reading this forum that we LOVE a challenge. The tougher the better (as long as we solve it!) :-)
jim

 

Yes, that's what I meant, two switches. On the F-series trucks, I have seen the same arrangement but with the red switch pointing up. On my E-series it points down but looks like the same exact thing.
No way to get a photo, there is that steering assist pump wedged right in that space in front of the master cylinder. It's the kind of pump they use to run snowplows.


Ok, thanks very much again. What I meant was it's the kind of problem where I just need to get in there and do the work and trace the wiring out, since it's jacked up with all the handicap stuff and other mods and none of us have any idea what was done to the van.

Yeah I have that suspicion as well. Like the guy I heard of who had to swap out boxed rebuilt alternators three times before getting a good one.
The odds sometimes stack against you...
Tried that on the original one, rotated that plastic thing on the servo to unhook the cable and it pulled nicely through the sheath.

I don't think there is a wrong direction at this point!
I guess the fact that I couldn't find any one else with this problem was a big hint!
I'm on a business trip right now, I can get back on it end of this week.
Cheers

 

Hans please let us know what you eventually discover or how else we can try to help. This is quite perplexing so far------sorry can't be more helpful.

 

Hi Jim, the hand control is completely mechanical, just a big lever that comes out the left of the steering wheel. The lever runs a complex linkage that pushes on the normal gas and brake pedal arms. So the pedals are unaffected and you can use them like on any normal van.
Now I want those kind of controls for all my cars! Love being able to run regular traffic with my feet at rest.

That's what I think! I just have to get in there like a honey badger and trace it out.
Unfortunately you have to drive the car to get it to do it. If I knew someone with a chassis dyno...

 

Hi again,
Some progress but no change in behavior. Removed some of the handicap systems and other stuff, pulled out the plow pump in the front so I could get in there.
Looks like the recall work was done, there is a harness coming off the master cylinder red switch, has two fuses each with a 2 amp fuse, both good.
After this, I took it out for a drive and wow, the cruise worked, thought it was all good, then *snap* and shut down after about 10 seconds. If I press OFF and then ON again, it will set and hold once more but shorter duration, only a few seconds.
The click is more of a snap sound or a clack, it's not just a normal soft relay click like a turn signal. The sound is reliable, every time it shuts down. I think it's coming from down low below my knees, but so hard to tell while driving.
Does anyone have a wiring diagram for the cruise system for this van, 98 E350 with V10?

 

Hey Hans-----sorry you've not cure this annoying thing so far. This loud click or clack confuses me as I've never experience anything similar on a standard configured E-Series. When mine was shutting off by itself it was completely silent, replacing the master cylinder cancel switch forever cured my problem.

Look at Advanced Auto Part's website for their free schematics---its free but IIRC they want you to create an account---small price if they have anything useful.

While its not quite as quick full factory schematics can be found through eBay, Ford calls them EVTM's or Electro-Vacuum Troubleshooting Manual. Without digging too deeply I found this:

1998 Ford Econoline Club Wagon Electrical Vacuum Factory Manual | eBay

Price isn't spectacular but there might be others available under the Manuals & Literature category.

 

Also some diagrams here, Hans:
BBB Industries - TSB's & Wiring Diagrams

Didn't find specific cruise control but some power distribution diagrams. The sound you describe makes me thing thermal circuit breaker, self-resetting? jim

 

JWA and jimandnena, thanks for the input!
I had the EVTM for my previous 86 E350, maybe I'll go that route because I will probably have this van a while.
jimandnena, I did find the diagram on that web site, I clicked on the Wire Diagrams button, then selected Engine for system and under subsystems it showed Speed Control! That's what I need right now, thank you.
I also had the thought for a circuit breaker and saw the there was an aluminum colored oval can right there on the fuse panel, a 20A self-resetting. The PO had stuck a tap under one leg of it to run some lights. Pulled that out and fixed the contacts and got a new one. That was just before the last trial where the speed control worked for 10 seconds or so, and that was a lot longer than it has lately. So maybe that is on the right track. Maybe something drawing heavy than normal on that breaker already and the cruise servo pushes it over 20A? As good a guess as any, I'll go figure out what else is on that breaker.