cruise control problems

[mike86ttype]

My cruise control has to worked since i bought the car 3 years ago. I get no light on the dash and i have did Salvagev6 cruise control test on the module wires so the brake switch is set up right and that test passed. what is next to test.


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THIS IS THE TEST I DID
After you turn the cruise to ON at the stalk measure power at the black box cruise module wiring.

You need to see +12 on the gray wire or PIN A of the box, and power on the brown wire PIN G of the box.

G is thru the brake switch so if that isn't making contact pushed into the brake pedal to make contact far enough the cruise won't work.

Don't step on the brake while doing the test either.

Next test leaving the Cruise switch ON at the stalk would be the set switch test, push that one and look for +12 while holding the switch on the dark blue wire PIN L on the cruise box.

Last test is the resume/accel. switch when pushed should give you +12 on the gray/black stripe wire PIN M on the cruise module.

Cruise control switch still in the ON position for all tests. Foot off the brakes.

The 5 Amp Cruise fuse must be good for all tests and power available on the pink/black wire where the stalk wiring meets the wires going to the cruise box module under the dash near the steering column, it has it's own funky looking 4 cavity flat connector. Wiring from the cruise stalk looks like telephone wires in a black jacket.

It's easier to test at the black box module sometimes however which is why I started there with the signals you need to see.

Module doesn't need the connector to be plugged into it for this testing so just take a reading for those +12 signals from the large plug going into it.

IGN Key on for the tests as well and check that cruise fuse.

 

[mike86ttype]

UPDATE:
With the module pluged in i hear a click under the hood but the cruise control light does not come on. I have tested the white(PIN B) wire at the module plug and do not get a ground out of it while the cruise control is on. Could my module be bad.

 

[RT87]

It may sound foolish, but the best way I have found to troubleshoot the system is with a known good cruise/turn signal switch. If you have access to one, plug it into the harness without installing it into the column. Turn on the ignition and engage the cruise control. You should get the cruise light and hear the click from the actuator in the engine compartment. The switch itself houses the majority of the cruise circuits and is usually the cause of the problem.

 

[mike86ttype]

cruise control switch is new. i just installed it last week with my new column. i think its the module. thanks

 

[salvageV6]

If you get the proper signals for the test it is time to take the car on the road and go over 25 mph to test the system.

I don't think the light comes on until set while driving over 25mph.

Tests are only simple electrical ones to make sure you have the proper initial signals from the stalk before you go out on the road to test it.

Make sure the vacuum brake switch is working and attached as well.

 

[mike86ttype]

ok took it out and the cruise light came on but it doesn't hold mph. I don't think it has a vacuum leak because my boost gauges has a negative and it looks like it was before i hooked the vacuum line up to the cruise control. So i got some progress I have CRUISE light. :biggrin:

 

[salvageV6]

First you need to make sure you have good vacuum into the cruise control servo under the hood check it at idle.

Then check to see the cruise servo output cable moves freely and controls the throttle movement.

Terminals C + J with an ohmmeter module connected to wiring, should be 30 to 55 ohms with a good digital meter.

The measure K + J with an ohmmeter and also should be 30 to 55 ohms.

Measure F + H pins and should be 15 to 25 ohms.

 

[mike86ttype]

i have vacumn at the servo and the cable moves freely. what terminals am i checkin the ones on the module or the servo. thanks for ur help

 

[salvageV6]

Those were module connector pins.

The book said to use IGN ON and cruise switch ON but I don't think that's necessary, try it both ways key off and on but if you use Key ON make sure you test for voltage across any of those combinations listed to check ohms on, you don't want any voltage readings when checking ohms.

I'd also double check to make sure when the brake pedal is not touched and the arm is all the way up it presses the cruise vacuum switch and closes it tightly so there's no venting.

That's the number 1 failure mode of the whole thing.

And it can be loose in the bracket and pop out even if you set it correctly once, just double check it for proper operation.

Module failure is kinda rare actually.

People hacking stuff up is usually what disables them.

 

[mike86ttype]

Terminals C + J 65ohms

The measure K + J 65ohms

Measure F + H 265ohms

 

[salvageV6]

F+H don't look good to me, others are within experimental/meter/leads hookup error.

So I'd take a reading at the cruise control servo position sensor itself under the hood and measure termianals D and B on that connector, which is between the light blue and black stripe wire, and the tan wire.

Should be 15 to 25 ohms there.

Over 25 ohms at the servo itself indicates it needs replacing.

Under 10 ohms at the servo and you need to check the ground wire which is the light blue/black stripe wire, which you could measure to ground in a key off test at any time to check ohms between a good ground and that wire in the connector.

Time to check connections and readings at the servo itself.

Obviously to do so, you need to measure the pins on the servo itself not the wiring connector alone, excepting for the light blue/ black wire to ground test, you could leave the wiring connector in place slid back a little, or take it off completely once you find the right two pins on the servo to test directly.