The clear lights are tied into the dome light, so they should not come on when you step on the brake. The red lights should come on when the brake lights come on.

 

Thanks for the suggestion glc. I did some testing this morning and confirmed that the recall harness is in good shape. Using a VOM, I tested the switch and determined that the switch is normally closed (NC), and when you step on the brake, the switch opens. I then ran the same test again through the recall cable and got the same result, so there is continuity through the cable meaning the inline fuse is good. Just to be sure, I bypassed the recall cable altogether and plugged the original harness directly into the switch on the brake master cylinder. I get the same result running the self test, (which is I get no cruise light flash when I go through the sequence of switches and get to the Resume switch), and the cruise still operates the same - it won't hold the speed when you engage it. So, I think I've eliminated the switch on the brake master cylinder and a blown fuse in the recall cable as a source of my trouble.

 

Hi sscully. The self test did not complete to the servo operation. As I said in my original post, when I go into self test mode, I get the initial flash holding down the off button. I then release it and get a flash when I press the ON button. BUT, when I release the ON button and press the Resume button, no flash. So, I can't get through the entire self test sequence. Missileer had the same symptoms when he ran the self test (the post I quoted) and I was curious if he figured out what his problem was - because based on the self test, I probably have the same issue he did. Based on the self test results I'm seeing, I'm not sure if I have a problem with the switches or the servo itself.

 

Does anyone know if there is a switch on the brake pedal that is involved with the cruise control on the 2002? This afternoon I tried wiggling the wire harness that appears to connect to sonething on the brake pedal. After doing so, my cruise control self test results have changed. Now, I get s flash when I hit the On button, as well as the Resume button, but, no flash on the set/accel or coast buttons. Any thoughts?

 

You are not even to the point of testing the servo in the self test.

That leaves you at time to test the switch to see if it is bad.

At the base of the steering column there is a 6 pin connector ( 2 rows of 3 ) for the switch.

the wire pair is Light Blue w/ Black stripe & Dark Green w/ Orange stripe.

unplug the connector, and the side towards the steering column, use the Ohm or resistance setting on your meter to check the resistance values

Resume is 220 ohms
Set / Accel is 680 ohms
coast is 120 ohms.

The brake pedal position switch is also part of the cruise control system, but this feeds the servo control unit to the brake applied input, to shut off the CC. This is in addition to the secondary CC deactivation switch ( with the recall harness ) that is 125 PSI or more is registered on the switch, the servo is triggered with the change on the brake pressure switch input terminal.

 

Hi SSCULLY:
Thanks for providing the procedure to test the steering wheel switches. I think I now know why the self test is not completing.


Using two different VOM meters (Fluke 77 and Fluke 8022B), I tested the switch resistance values following your procedure.


Using the Fluke 77 auto-ranging meter first, the Resume button measured 2226 ohms, the Set/Accel button measured 680 ohms, and the Coast button measured 122 ohms.


Never having completed trusted an auto-ranging meter, I then ran the same test using the Fluke 8022B meter. On the 2K range setting, the Resume button measured "infinite", the Set/Accel button measured 0.681 and the Coast button measured 0.120. On the 20K range setting, the Resume button measured 2.22 ohms, the Set/Accel button measured 0.68 ohms and the Coast button measured 0.12 ohms.


It would appear that the Resume button is out of range by a factor of 10 and would explain why I was not getting past the Resume button in the self test procedure.


I'm not sure the steering wheel switches are my only problem here, but I will fix one thing at a time and move on to the next.


I will update the group once I replace the steering wheel switches.


Thanks again for the switch testing procedure and specs on the switch values!

 

Hi SSCULLY:


So a replacement set of switches arrived in the mail today. Before I went through the hassle of installing them, I thought I would test the resistance values for the Resume, Set and Coast buttons on the replacement set. I'm getting exactly the same readings for these replacement switches as I have for the ones in my truck. Are you sure that the Resume button is supposed to read 220 Ohms and not 2200 Ohms? (Both sets of switches I have measure 2200 ohms for the Resume switch). I'm thinking there are two possibilities here: 1) my replacement switches are faulty in exactly the same manner as my currently installed switches, or 2) possibly the original post has a typo and the actual value for the Resume is 2200 Ohms and not 220 Ohms.


Any additional info from you or anyone else on this thread as to what the actual resistance value for the Resume switch should be would be deeply appreciated.


Thanks!

 

You were close with the typo; Not wearing my reading glasses when reading the paper copy of the manual.

I should have posted this.



Let me know if you cannot return that switch.

 

No worries on the switch SSCULLY, it is returnable. Thanks for including the diagram in your response. At least now I know that fuses and the steering wheel switches are not the issue. But this now leaves me wondering why the self test is not completing. I'm getting a flash from the On button and from the Resume button, but nothing from the Set/Accel or Coast buttons. The search for the root cause continues....

 

That is great news.

The next step that I can think of it to test the resistance at the servo control under the hood, to make sure there is nothing wrong with the wiring from the connector you tested at in the cab of the truck.

Same wire colors at the Servo under the hood ( the A and B arrows ).





If you get the same resistance values at the servo connector, the last thing I see as the issue is the servo controller itself.

 

This is great info! Thanks for the additional diagrams, especially the one that has the pin-out of the servo connector. What I plan to do is test all the inputs right at this connector. I'll be able to test the steering wheel (control) switches, the brake pressure switch input, the BPP switch and power on pin 7. If all the inputs test good at this connector then that would seem to imply the servo itself is bad since we can't get through the self test. Is there a way to test the vehicle speed input without the vehicle running/moving?

 

As far as I recall, the only way to register a change on the VSS is to have the vehicle moving.
- I seem to recall the value is variable voltage range depending on the speed of the vehicle. Do not take that as fact, it has been some time since I looked..

 

The VSS sensor of vehicles this age typically output an AC signal with a frequency that varied with the speed of the vehicle. The voltage remained relatively constant across the speed range of the vehicle.

 

Thank you SSCULLY and projectSHO89 for the information on the VSS input. Here is an update on my troubleshooting...


Although I had previously tested all the switches independently and verified they were working, using the diagram showing the pin-out of the Cruise Control Servo unit's connector, I thought it would be a good idea to these the switch inputs right at the servo connector to eliminate any sort of wiring problem. I verified that I had +12v at pin 7 with the ignition switch in the "run" position. I then tested the Brake Pressure Switch input on pin 9. I had +12v until I stepped on the brake pedal, and then it dropped to 0v. I then checked the operation of the Brake Pedal Position switch on pin 4. I had 0v there until I stepped on the brake pedal at which time I saw +12V. I put an ohm meter across pins 5 and 6 and measured 2200 ohms when I pressed Resume, 681 ohms when I pressed Set/Accel, and 122 ohms when I pressed Coast. I then connected the Ohm meter pin 5 and ground and got 1 ohm when I pressed the Off switch.


Since all the inputs appear good right at the servo connector, and I am unable to complete the Cruise control self test, I have concluded the Cruise Control servo unit is bad. There is no way I'm paying Ford $535 for a new one, so I am taking a gamble on one off of Ebay. I'll update you guys after I receive the replacement servo and get it installed. Thanks for all the troubleshooting assistance thus far.

 

OK guys, here's the latest. My replacement servo arrived yesterday and I tossed it into the truck this afternoon. I tried running the self test and the self test failed (did not complete) in exactly the same place as my original unit. BUT, I decided to take the truck for a roll down the interstate anyway and much to my surprise, the cruise control is now working again - all functions, set, accell, coast, disengage when braking, disengage when pressing off, etc. I have no idea why my truck won't complete the entire cruise self test sequence, but all functions on the cruise are working again now that I have replaced the servo.


I would like thank all those who provided information and assistance in the diagnose and repair of my cruise control. I learned a whole lot more than I expected to in the process, and the repair ended up only costing me $26 for a used servo unit (that also came with the bracket and cable). I'd hate to think what this repair would have cost if I had taken the truck to my dealer.