DOZENVALVE

been following these steps.


This is straight out of the FSM quoted by "SantaClaus" from another thread-

1. Turn the ignition switch to on position.
2. Push speed control switch to on position.
3. Connect the negative lead of a voltmeter to a good chassis ground near the servo.
4. Disconnect the four-way connector going to the servo.
The blue wire with the red tracer should read approximately battery voltage. If not, check for loose connections, brake switch adjustment or, repair the main harness as necessary.
5. Connect a jumper wire between the male and female terminals of the blue wire with red tracer. ( note I am reading this from the service manual and not looking at it on my truck was apparently what they want you to do is supply electricity to the servo) the other three male terminals from this road should show battery voltage if not replaces servo.
6. Turn the ignition off. Using an ohm meter, connect one lead to a good body ground. Touch the other lead to the black (BK) or terminal in the four-way connector of the main harness. The media should show continuity. If not repaired or ground circuit.
If this is not find your problem let me know and I can go on down the list.

Testing the PCM cruise control port

The next section; electrical test that powertrain control module.
1. Unplug 60 way connector for powertrain control module located on the left fender.
2. Connect negative lead of old mayor to the ground.
3. The following test, the ignition switch must be in the on position. ( when you unplug the control module turn it so you're looking at the business end the top row are numbered 1 through 20, the next row 21 through 40, the next row 41 through 60, best I can tell you without a picture ) refer to figure for control terminal locations. Touched a positive lead of the voltmeter to the terminal in cavity number 33. With the speed control switch in the off position, the voltmeter should read 0 V. With the speed control switch in the on position, the voltmeter should read battery voltage. If not fix it.
4. Touch the positive lead of the voltmeter to the turmoil in the cavity number 53. As in step three, the voltmeter should read 0 V with the switch in the off position and battery voltage with the switch in the on position.
5. Touched a positive lead of the voltmeter to the terminal in the cavity number 48. With the speed control switch in the off position the voltmeter should read 0 V. The switch and on position the voltmeter should read battery voltage. Pressing the set button should cause the voltmeter to change from battery voltage to 0 V for as long as the switch is hailed. If not perform the speed control switch test. If the switch is not at fault, and then check the main harness and repair as necessary.
6. Touch the positive lead of the voltmeter to the terminal in cavity number 50. The voltmeter should read 0 V with the speed control switch in either the off or on position. With switch in either resume or set position, the voltmeter should read battery voltage. If not performed a speed control switch test.
7. Touch the positive lead of the voltmeter to the terminal in cavity number 49. Should read 0 V with the switch off. With the switch on, should read battery voltage. The voltmeter will continue to read battery voltage when either the set or resume switch is pressed. If not perform speed control switch test.
8. Turnkey off. Use in all major, connect lead to good body ground and touch the other lead to the terminal in cavity number 29. With the break pedal released, the meter should show continuity. When the pedal is depressed the meter should show open circuit.




as in step 4 of the first section, I disconnected the servo and I am getting no voltage at the harness


then in the second section at step 3, I have no voltage at the PCM.


yes my cruise switch is on and my key is on.


somebody is going to say clock spring but I am finding that hard to find because everything else is working, horn etc. never had a problem.


with the CC I have never once seen a light on the dash or had it work since I got the truck, nothing.


any ideas? gottta get this fixed before my next 6hr drive to work. cant stand it any longer!

DOZENVALVE

I have check the first 12" of wiring down fro the clock spring and it is good. also checked the first 12" of wiring back up from the servo and also good

could the switch on the steering wheel be bad?

DOZENVALVE

with the key on, I unplugged the harness behind the horn cover, and I have 0 voltage coming up to the switches. no voltage to the switches... maybe it is that clock spring?

MARF75

Check the brake switch and wiring. Must be a 6 wire switch. Ask me how I know.

DOZENVALVE

Brake switch as in the brake light switch on the pedal?

Hillbilly66

Yes, if it is not adjusted properly cruise control will not work. It is possible for it to be out of adjustment just far enough that cruise won't work but still allow brake lights to work

DOZENVALVE

Okay. Interesting you say this. It has been way out of adjustment since I got the truck. But I just fixed it before I started working on the truck tonight. The button on the switch is fully depressed when I release the pedal.

Before, the bracket r mounted on was sitting a little crooked to the pedal, and it kept getting pushed through the bracket, and the brake lights would stay on because the button would Not be depressed all the way. I bent the bracket square with the pedal and now it seems to be perfect

Yet still no cruise. I look at the brake light switch wiring tomorrow.

thrashingcows

Do you have a FSM? If you do, then work your way through the diagnostics in there....they are very extensive. Shows how to test your steering column cruise switches, your clock spring wiring, brake light, PCM pin out etc.

My cruise works, but it will not hold a steady speed, always wants to speed up. I have been through the FSM diagnostic 3 times, and everything checks out perfect. I have replaced steering column switches, cruise servo, brake light switch, and it still does the same thing. Only thing I have not done is replace the PCM.

So just so you know, even if you get it working, it might not work perfectly.

j_martin

The wheel switches on these things are cheap. On one set I had, the set/decel switch was marginal, and it would go into cruise at random times, and also drop out at random times. I imagine if the other switches were noisy, it's do weird things also.

I spliced one set together from 3 I had, 2 in good mechanical shape, and the other damaged. I'm going to see if I can repair some of the remaining switches and wire them into a set.

I could use some bad switch sets for experimenting. Maybe I can help some folks out. I think I can get replacement switches from an electronics supplier. I have the tools to solder them in, and repair the PC board in one.

MARF75

J, I may have some switches. I'll check and PM you if so.

DOZENVALVE

I do not have an FSM

torquefan

I think a FSM at this point will be vital in continuing your diagnostics. Regarding your earlier comment about not having power at pin 33 on the PCM, you can use the proper diagram in the manual to trace back through that circuit, see where the power is supposed to originate from, and zero in on the cause.

DOZENVALVE

This sucks! Really wanted to get this fixed before I go back to work after thanksgiving.

Where can I get an FSM?

DOZENVALVE

I need a wiring diagram for the clock spring wiring and how to test for voltage just before the clockspring

or a link to an FSM

thrashingcows

Have you looked through the sticky? I know there is some FSM stuff there....just not sure for what year.

If I was home I'd check my PCM...I remember coming across a complete PDF files of the 92/93 FSM. I'm sure I book marked, or saved them.