Cruise Control doesn't work - 2000 Explorer Limited

[dropdtop]

OK busted out my schematic,,, on the cruise control servo (Right Rear of Engine Compartment) there should be 8 wires going to the unit from the plug.

the Light Blue W/Black tracer wire is the one that comes from the column... it should have 12V only when you push the ON button and then it should be a 680Ohm resistance when you push the SET/ACCELL BUTTON.

The TAN W/Light Blue wire is the brake input... it should be grounded when the brake is OFF and then show 12V when the brake is applied

The GRAY W/Yellow wire is the 12V ignition wire

Black is of course ground

ORG W/light blue if the output for the dash light

Black W/Yellow wire is from the brake pressure switch and looks to have 12V when the vehicle is running.

 

[Dono]

Thanks, I'll get some help and perform the tests.

 

[vroomzoomboom]

If you need it, just let me know don

 

[Dono]

Light Blue W/Black tracer wire is the one that comes from the column... it should have 12V only when you push the ON button and then it should be a 680Ohm resistance when you push the SET/ACCELL BUTTON.

This wire shows 9.32v all the time, there is no change when the button is pushed.
For the 6800 ohm, that can't be done with the engine running, so Im not sure I could test that. ISSUE

The TAN W/Light Blue wire is the brake input... it should be grounded when the brake is OFF and then show 12V when the brake is applied
Brake off: 0v
Brake on 9.5v

The GRAY W/Yellow wire is the 12V ignition wire
This goes to 12v when the ignition is on. OK

Black is of course ground
OK

ORG W/light blue if the output for the dash light -
No need, I was able to get the cruise light to flash in the diagnostics mode

Black W/Yellow wire is from the brake pressure switch and looks to have 12V when the vehicle is running.
12v constant, press the brake and voltage drops to 0. OK

So, best guess? Maybe I need to run a 12v supply from the 12v side of the battery to the Light Blue/Black tracer wire and go for a drive?

 

[dropdtop]

OK nevermind the 12V,, i looked at it wrong on the schematic sorry.

you first have to unplug the connector from the module.

there should be a Dark Green w/orange tracer. that is the Ground return for the controls so put your meters negative lead on that.

they way it looks on the schematic is that when you push Set Accell it should be 680 ohms between the Dark Green W/Orng and the LT Blue w/blk wire

the ON button is drawn differently,, it looks like it gets voltage thru the coil of the horn relay (minimal current) and flows thru a 1000ohm resistor. so with the module unplugged the LT BLUE/Blk wire should be dead and should read a small voltage when the ON button is pushed.

Light Blue W/Black tracer wire is the one that comes from the column... it should have 12V only when you push the ON button and then it should be a 680Ohm resistance when you push the SET/ACCELL BUTTON.

This wire shows 9.32v all the time, there is no change when the button is pushed.
For the 6800 ohm, that can't be done with the engine running, so Im not sure I could test that. ISSUE

The TAN W/Light Blue wire is the brake input... it should be grounded when the brake is OFF and then show 12V when the brake is applied
Brake off: 0v
Brake on 9.5v

The GRAY W/Yellow wire is the 12V ignition wire
This goes to 12v when the ignition is on. OK

Black is of course ground
OK

ORG W/light blue if the output for the dash light -
No need, I was able to get the cruise light to flash in the diagnostics mode

Black W/Yellow wire is from the brake pressure switch and looks to have 12V when the vehicle is running.
12v constant, press the brake and voltage drops to 0. OK

So, best guess? Maybe I need to run a 12v supply from the 12v side of the battery to the Light Blue/Black tracer wire and go for a drive?

 

[Dono]

Thanks Brad, I think your method of using ohms to test instead of voltage will work better.

I'll test tonight.

 

[dropdtop]

your gonna have to. that's how the system works each button has a different resistor built into it... the module determined the button you pressed by reading the resistor value. only the on button looks to actually have a voltage source.

Thanks Brad, I think your method of using ohms to test instead of voltage will work better.

I'll test tonight.

 

[Dono]

Ok, Ive beat this to death. Definitely the on button in the switch pack.
using ohms only...Cruise module unplugged.
One lead at the light blue/black trace at the cruise module connector under the hood, the other meter lead on the same wire (light Blue/black trace) going in to cruise button pack at the steering wheel. 0 ohms. The wire, and the path thru the clock spring is good. No broken wire, lifes good!

Next step, move the lead from the light blue/black trace wire at the switch pack to the Yellow/light green wite in the steering wheel. Should be open, then when the on button is pushed I should see approx. 1000 ohms. Nope. Open. No worky.

Now, for giggles (And to double check the schematic for accuracy) I moved the test lead from the yellow/light green trace wire to the Dark green/orange trace wire at the switch pack (the other lead still on the Light blue/black trace wire). This should let me test the other cruise buttons.
Push 'Resume', meter reads almost exactly 220 ohms Perfect
Push 'Set/accel', meter reads 660 ohms. 20 ohms off..10% rule...PERFECT
Push 'Coast', meter reads 120 ohms. PERFECT

So, unless Im really missing something, it has to be the switch pack. Even though I take the switch pack apart and test the physical on switch and it tests good, there has to be an issue on that pcb board somewhere.

Blueka is sending me that switch pack, so I'll know shorty for sure.

Brad, does this make sense?

Oh, btw, I made that issue with the shifter staying locked in park worse. I guess once it becomes a permanent issue it will be a lot easier to fix. I guess the shift lock solenoid has to be under those steering column covers right at the instrument cluster since I had that apart on sunday making the issue worse. These are extremely small issues, and the truck is wonderful. I'm just being picky with it because its new to me and in such perfect shape.

 

[dropdtop]

I have too look again but the ON button will not have resistance between the 2 wires. it only sends a voltage to the light blue wire thru the coil of the horn relay.. so with the meter on a good engine block ground and the positive on the light blue with the key on you should see a voltage less then 12v.

 

[Dono]

"One lead at the light blue/black trace at the cruise module connector under the hood, the other meter lead on the same wire (light Blue/black trace) going in to cruise button pack at the steering wheel. 0 ohms"

This quote was just testing the light blue/black wire from the cruise module to the button pack. It is just a straight wire I was testing to make sure it didn't have a break in it anywhere. Once I go across the switch (One lead on Light blue/black trace wire and the other on the Yellow/light green trace wire) that the meter reads infinite resistance if the 'on' button is pressed, or not. Im thinking that when the button is pressed I should have seen 1000 ohms.

That tells me its the button pack.

 

[dropdtop]

you have to leave the yellow wire out of the mix for the ON button.. the is the ground return for all other buttons except the ON.


to test the on you have Togo from vehicle positive battery terminal to the light blue wire... only then you should see around 1000 ohm. but it also passes thru the coil of the horn relay so what ever the coil ohms to you have to add that.

what I would do is measure the light blue wire for voltage with the key on and press on and see what you get.

 

[Dono]

Solved! Thanks Blueka!
It was the switch pack on the steering wheel.

Its interesting that the momentary 'on' switch worked, but something is wrong with the board assembly.

 

[dropdtop]

Glad it solved the problem.. that wierd that it just went like that. sucks cause those buttons were immaculate.

Solved! Thanks Blueka!
It was the switch pack on the steering wheel.

Its interesting that the momentary 'on' switch worked, but something is wrong with the board assembly.

 

[Dono]

I know, The buttons that Blueka sent me look pretty good. For the 2 screws it takes to swap them, I think I will go ahead and do it just so they stay the same.

Thanks for your help on this.