Cruise control recall

[MBDiagMan]

Why can you not imagine that they would have updated the switch? They change parts, parts designs and suppliers all the time. We are just fortunate that they now have good enough tracabilty of where particular parts went. Before the days of MES, MRP and other expensive software systems, they would have had no idea where a particular batch of parts went. If you have a model later than those in the recall and your switch is dry, then relax. It won't hurt to pull the connector and check every once in a while, but you are okay. In your case, it would be good to add the operation of pulling the connector and looking inside for brake fluid as one of those little checks that you do at every oil change. You do give things a quick check at oil change time don't you? It is a very good practice to check things while you're underneath the car at oil change time. Give steering components a quick shake, look around with a drop light for fluid leaks, if you have four wheel drive look to see that your CV joint boots are not torn, etc. Even though you don't have to underneath to check this switch, that would be the perfect time interval to give it a look see. Just get in the habit of checking it while you are doing all the other quick checks. Remember folks, don't panic! Education is your best tool to prevent this from happening and good maintenance is the best key to keeping your car running trouble free for the long term. End of sermon, Doc

[snoVVman]

Gee, thanks for the sermon, I needed that.

No one is panicking. Having read and seen the pictures of destruction, folks are just interested in minimizing their risk. I am fully aware of the statistics and probability, even so, no one wants their garage, home, and everything else go up in flames. Insurance might pay and litigation might help, but no matter what happens, you lose. No one wants that.

It is a well known fact that manufactures update design and specifications of components. This is usually reflected in the part number. Indeed, the supplier could have improved the switch design between 00, 01, and 02, while maintaining the circuit design. But it is just as likely, in this particular situation, that the switch design did not change. Change typically occurs when they find a problem or a technical reason to change. Simple economics. So when did they find the problem?

The point here is that I do not intend to wait until every oil change to check and hope that the time in between I am not at risk. Why buy lottery tickets? You could win, albeit unlikely. Why go through the trouble of verifying that I am not at risk? My life could burn, albeit unlikely. I wish to continue to use my cruise control, therefore, I intend to verify that I am not at risk. My query was intended for that.

I'm sure your maintenance tips are useful for many people, and I agree with your recommendations. Realizing that the following comments don't generally apply to the participants here, but for those who don't know what a CV boot is, and don't care, and go to a quick lube, they are not likely to want to address the problem themselves anyway.

I intend to check the part numbers of this switch between the years. This certainly gives a clue to any design or manufacturing updates. It is not uncommon that recalls are only expanded later due to a variety of reasons--most of them to benefit or to serve the convenience of the manufacturer. Just because my vehicle is not part of the current recall, it doesn't mean it's not at risk. No one, as far as they knew, were at risk prior to the current recall.

That said, peace to you, and thank you for your contribution.

JAMES.

[MBDiagMan]

I guess you misunderstood me. I was not suggesting that you take all this likely. I was making a suggestion.

Your truck is NOT suspected. It sounds to me like they know where these particular switches went. They specified all 2000 models and 2001 Super crew cabs. That indicates to me that they know which trucks got the switches with the design that is prone to leaking.

No, the circuit did not change, but if the switch is updated, there's no reason to panic. My suggestion for checking it periodically was actually a "just to be safe" type of practice. If you had a 2000, or a 2001 Super Crew, I would not be happy to see you simply inspect it periodically, but you don't have a suspect switch so checking is an added precaution.

I have a 2000, so I inspected, found it dry and disconnected it. I had to make a pretty long run yesterday, so I inspected the switch to ensure that it was dry and connected the switch. After I got home from all that driving I disconnected the switch.

Remember, there is also another very important indication of trouble, the cruise control stops working first. So, if you don't use the Cruise, disconnect it and forget it. If you do use the Cruise then you will get this warning sign. I would think that watching for the failed Cruise warning sign coupled with spending about 15 seconds every few months to inspect the switch would be adequate overkill and allow you to sleep at night.

Yes, there is panic in the air. There was one person here or on another forum that disconnected the switch and they STILL will not park it in the garage. Without the connector on the switch, the fire can't happen. In my estimation that is panic.

There is danger in everything. I could walk out to the mailbox tomorrow and get hit by a truck. If someone is so afraid that their truck will burn even with the circuit disabled, that's panic, or at least paranoia.

Have a great day,
Doc

[tinytrixie]

My son has a 1997 F150 4x4 SB that the cruise sensor was leaking on a couple of years ago. His cruise had also quit working. We took the sensor off my '95 F250(same switch) because I didn't have cruise & it was still unused. His cruise started working again! Is there something different about the models in the recall? From the looks of the part it seems to be the same. Anyone else seen this in models outside of the recall?

[MBDiagMan]

The difference apparantly is that some of the switches were built by a different manufacturer or a different method and are prone to leaking.

I think that if you have a truck with the same circuit design, regardless of year model, it would behoove you to take the extra 15 seconds at every oil change time to pull the connector and look down into the switch with a flashlight to see that it is not leaking. If it is leaking, get one of the new switches when they are available and leave the connector off until you replace it.

Good luck,
Doc

[deano2]

What I don't understand is ... what is actually burning? Brake Fluid is not flammable. Try it, pour a little out in a small lid and put your lighter to it.
I have a 2000 F150 4x4 and have unplugged the switch connector according to the picture that was posted earlier. Thanks for the picture, by the way. I'm waiting to be contacted by Ford, but still don't know what the fuel is that's igniting when the switch gets too hot. I keep hearing brake fluid, but I have my doubts.

[ALL4RD]

This is a copy of the recall from NHTSA

Make / Models : Model/Build Years:
FORD / EXPEDITION 2000

FORD / F150 2000

FORD / SUPERCREW 2001

LINCOLN / NAVIGATOR 2000

Manufacturer : FORD MOTOR COMPANY

NHTSA CAMPAIGN ID Number : 05V017000 Recall Date : JAN 27, 2005
Component: VEHICLE SPEED CONTROL:CRUISE CONTROL
Potential Number Of Units Affected : 738490
Summary:
ON CERTAIN SPORT UTILITY VEHICLES AND PICKUP TRUCKS, THE SPEED CONTROL DEACTIVATION SWITCH MAY OVERHEAT, SMOKE, OR BURN.
Consequence:
THIS CONDITION COULD LEAD TO A FIRE. FIRES HAVE OCCURRED WHILE THE VEHICLES WERE PARKED WITH THE IGNITION 'OFF.'
Remedy:
AS AN INTERIM REPAIR, OWNERS WILL BE INSTRUCTED TO RETURN THEIR VEHICLES TO THEIR DEALERS TO HAVE THE SPEED CONTROL DEACTIVATION SWITCH DISCONNECTED. AS SOON AS REPLACEMENT PARTS ARE AVAILABLE (EARLY APRIL 2005), OWNERS WILL BE INSTRUCTED TO RETURN TO THE DEALERS FOR INSTALLATION OF A NEW SWITCH. OWNERS SHOULD CONTACT FORD AT 1-800-392-3673.
Notes:
FORD RECALL NO. 05S28. CUSTOMERS CAN ALSO CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S AUTO SAFETY HOTLINE AT 1-888-327-4236.

[Aftrmidnite]

Brake fluid is flammable, flash point is around 270'F open cup, closed cup is slightly higher. Boiling point is around 430'F.

[kntryboy]

I have not looked at a wiring schematic for the cruise control circuit to see what kind of overcurrent device is in the circuit, but wouldn't a simple in-line fuse solve the problem until you can have the switch replaced?

[MBDiagMan]

It is an always hot 20Amp circuit. My question goes a little deeper. If it is just a signal why is it not a switched ground and why is it such a high current circuit.

If it is only a signal circuit then there has to be a reason for using such an unconventional signal. Maybe it was some sort of an afterthought. Either way, as far as I'm concerned as an Electrical Engineer, it was an engineering blunder, and for a few unfortunate people, proved to be an engineering disaster.

Have a great day,
Doc

[kntryboy]

I need to run down a wiring schematic............
Is the signal an input to the computer????????????
If so why such a large (20A) fuse??????????
Why not add an inline fuse rated at 1Amp??????
Is brake fluid conductive??? It must be short out to ground..........
and why does not the 20A fuse blow on a fault?

[MBDiagMan]

Yes, you do need to get a wiring diagram. You can get a Haynes manual at most auto parts stores for less than $20.

I'm not sure if it is a signal. I expect that it is, but that is very unorthodox to: provide a signal as a hot and make it on a high current supply.

The 20Amp fuse is part of the blunder unless it is somehow a power feed to the CC Amp. I have not checked the switch to ensure that it is a normally open switch. The diagram shows it to be, but this is part of the mystery that I have not fully investigated. The explanation I would have would be that they use a normally closed switch to provide power then interrupt the circuit to cancel the cruise. This would also be an engineering blunder. To me it appears that for some reason it was an afterthought.

If it is only a signal then that might be a solution, but I'm not sure that 1Amp wouldn't be enough to ignite if the resistance at the switch were just right.

I've never conducted flammability tests on brake fluids, but most all fluids are conductive, the question is at what resistance.

This question conflicts with your question number 3. The current obviously does not have to exceed 20 Amps to start a fire. For a 12Volt feed to flow 20Amps, you have a load of .6Ohms. That's pretty darn close to a dead short. 20Amps at 12Volts generates 240 Watts. Concentrate that much power in a tiny little area between the two terminals and that will make LOTS of heat without exceeding fuse rating.


What we don't yet know, and I think each of us don't learn first hand, is exactly how the switch fails. Is the switch portion down inside the switch exposed to fluid? Probably not. I am guessing that the diaphragm of the switch develops a leak allowing fluid up into the terminal area where it conducts enough to provide the right amount of resistance to develop heat.

I expect that Ford will never release information to this detail. The only way you or I will ever know is if we happen to know the Fire Inspector that investigates one of these fires.

Have a great day,
Doc

[kntryboy]

Ok, Mr. DBDiagMan, here is my interpretation of the wiring diagrams for my truck and results of my tests using a VOM meter…. Remember, this is just my opinion……….

1. There are three fuse circuits feeding into the speed control servo. Fuse 5 which is a 15 amp fuse circuit connects directly to pin 7 of the servo. Fuse 13 which is a 20 amp fuse circuit connects to the brake pedal position switch then to pin 4 of the servo, if you have a manual transmission there is also a clutch pedal position switch in series with the brake pedal position switch. Fuse 13 also connects to the deactivation switch, then to pin 9 of the servo.

2. The brake pedal position switch, which is located on the brake pedal, is the primary switch which deactivates the cruse control circuit. The deactivation switch, the one causing all of the problems and is located on the master cylinder, is a secondary switch per my interpretation of the wiring diagrams…..

3. The deactivation switch is a normally closed switch, and opens then you apply the brakes, this is a fail safe design. Why it is protected my such a large fuse, I do not know. Since, the deactivation switch is a secondary switch, I removed it from the circuit, and tested the cruise control, and everything worked fine, the circuit deactivates when I apply the brakes..….I would not recommend this however and I am sure Ford does not either………Since your are an electrical engineer, am sure you know how to do this…….

4. When the replacement switches are available, I will install the new switch and reconnect the circuit......

Of course all of the above is just my opinion….
“Git Er Done”

[MBDiagMan]

Country,

Everything you put down matches the wiring diagram that I have here. I would love to see a schematic for the servo black box.

I also understand what you are saying about disconnecting the deactivation switch and how you made this work. I also understand and am impressed that you are not going into detail about that here.

I could probably do this with my deactivation switch without too much safety risk because my truck is a manual transmission so the clutch switch gives me a quick way to cancel the cruise control if something were to go awry, but I work at home and don't drive the truck daily, so I think I'll just wait 'til April. If I have to take a long trip I will inspect the switch and if it's dry, I'll hook up the CC for the trip.

I, like you, am bumfuzzled about the 20Amp or 15Amp fuse UNLESS, this is the(or a) main power feed for the cruise control system. BTW, on my wiring diagram, it shows the navigator to be different from the F150/Expedition FWIW.

You have reverse engineered the wiring diagram well.

Have a great day,
Doc

[Racerguy]

The Ford shop manual maybe gives a clue as to why the big fuse. It says that the deactivation switch is an " Additional speed control deactivation device should the brake switch fail. Depressing brake pedal with additional pressure creating 125 psi in brake line, causes brake pressure switch to open, thereby removing voltage and current from electric clutch within speed control servo."
It would be interesting to know what the electric clutch does.
The same fuse also protects the Brake Pedal Pressure Switch and the Flasher Relay.