grande_guerre
grande mondiale
I pulled the cover off of my steering column and found a lump of wires. My cruise control does not work, never had before, and was wondering how i should go about trouble shooting it. any help would be appreciated.
Too Many Colors!
- Thread starter grande_guerre
- Start date
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Your cruise control works off of the engine vacuum so check the hose to the servo, which is close to/above the brake master cylinder.
fbrown3
New member
If you have a manual there should be a wiring diagram in the back if not, if not write down your colors from the cruise then go to the base of the column and check the colors at the harness plug to make sure they didn't change. If they are completely different you may have a different column/harness. If it doesn't match at all you may have to get the correct column. If every thing looks good follow it out to through the fire wall, then check to make sure all connections are good under the hood even the vacuum if applicable. Hope this helps some
Seabronc
New member
#1 does your horn work? If not, check fuse 16 20A The horn relay, (located under the dash supplies voltage to the Speed Control Switch. the path is; fuse 16, (yellow light blue dashed) wire, to C305A (the crescent shaped plug on the lower column), to the horn relay mounted on the speed control amplifier. thru the horn relay coil to c305 to the voltage supply brush to the Speed control switch (dark blue wire). The brushes are the little metal pins you are looking at when you pull the steering wheel. There should be (3) one connects th the Dark blue lead, a second one is the control signal brush which connects to a blue black hash marked wire which goes to the amplifier. The third brush is the ground brush which connects to a black wire. If this brush is not there, you will get inconsistant or no function from the speed control amplifier.
The amplifier is located under the dash to the right of the steering column. Inputs to the amplifier are fuse 6 via a white purple striped wire, fuse 1 thru the stop light switch, the clutch switch if manual shift or a jumper if automatic at C755a light green wire to the SCA.
Other inputs to the SCA are the speed sensor (located in the speedo cable between the upper and the lower cable, just under the break booster). Last but not least is the input from the servo motor. That is where vacuum comes in to the picture; 1. the hose to the main vac and a hose that goes back thru the firewall to a vacuum dump valve attached to the break peddle.
As you can see there is a lot of things to check and that can make it not work.
If you need it, I can probably scan in a diagram of the system.
Good Luck,
>-
The amplifier is located under the dash to the right of the steering column. Inputs to the amplifier are fuse 6 via a white purple striped wire, fuse 1 thru the stop light switch, the clutch switch if manual shift or a jumper if automatic at C755a light green wire to the SCA.
Other inputs to the SCA are the speed sensor (located in the speedo cable between the upper and the lower cable, just under the break booster). Last but not least is the input from the servo motor. That is where vacuum comes in to the picture; 1. the hose to the main vac and a hose that goes back thru the firewall to a vacuum dump valve attached to the break peddle.
As you can see there is a lot of things to check and that can make it not work.
If you need it, I can probably scan in a diagram of the system.
Good Luck,
>-grande_guerre
grande mondiale
My horn works fine, but I got lost after that... Did you just I.D. the path of the horn circuit??? :blink: What's number 2?
Seabronc
New member
Sorry, I started to break it up, but went on without a seperator.
1. voltage is supplied to the speed control switch (the buttons on the steering wheel) from fuse 15 thru the horn relay coil to the brush connected to the dark blue lead. Fuse 15 is hot at all times so you should be able to read it at the brush.
2. Grounding for the resisters built into the switch is provided by the brush with a black lead. You should be able to read a good ground path from here to battery - .
3. Signal from the switch to the Speed Control Amplifier (SCA from now on) is from the brush connected to the blue with black hash mared wire. With the steering wheel on, pushing the speed control ON button should give you voltage at the connector. (the voltage level changes depending which button you push).
4. Assuming the brushes are making contact properlyand that your horn works just fine, check the plugs to the SCA. It is located just under the dash to the right of the driver position with the horn relay mounted on the front side of it.
5. Check the vacuum dump valve located on the break peddle. Make sure it is not stuck. It has a plunger that dumps the vacuum to the Speed Control Servo (SCS from now on). Also check the condition of the vacuum hose connected to the plunger which goes thru the firewall to the SCS.
6. Check the condition of the hose from the SCS to the main vacuum source on the intake manafold.
7. Check the electrical plugs to the SCS (located near it). Take them apart, clean and reseat them. Before reconnecting them I suggest putting some dialectric grease on them to provide a moisture seal.
8. Check the connector to the Speed Sensor. The speed sensor is between the upper and lower speed cables just below the Break Vacuum booster, it sort of looks like a lolly pop. Take the connector apart, clean, add dialectric grease and reconnect.
9. Fuse 1 provides power to the SCA via the brake switch (light green with red hash marks) from the switch (light green) to the clutch switch (if not standard switch there should be a jumper plug in that connector) from there to the SCA.
10. Fuse 5 supplies voltage to the SCA via a white with pink stripe wire thru the connector on the steering column. (There are two sort of half moon connectors in that area when the SCA is installed. A truck without cruise control only has one) attached to the lower steeering column).
11. The other wires on the SCA go directly thru the firewall to the SCS.
So if all the above are good and you do indeed have all three brushes under the steering wheel you have three components left. The SCS, the SCA or the Speed sensor.
OK hope this helps you better than the first reply.
Good luck,
>-
1. voltage is supplied to the speed control switch (the buttons on the steering wheel) from fuse 15 thru the horn relay coil to the brush connected to the dark blue lead. Fuse 15 is hot at all times so you should be able to read it at the brush.
2. Grounding for the resisters built into the switch is provided by the brush with a black lead. You should be able to read a good ground path from here to battery - .
3. Signal from the switch to the Speed Control Amplifier (SCA from now on) is from the brush connected to the blue with black hash mared wire. With the steering wheel on, pushing the speed control ON button should give you voltage at the connector. (the voltage level changes depending which button you push).
4. Assuming the brushes are making contact properlyand that your horn works just fine, check the plugs to the SCA. It is located just under the dash to the right of the driver position with the horn relay mounted on the front side of it.
5. Check the vacuum dump valve located on the break peddle. Make sure it is not stuck. It has a plunger that dumps the vacuum to the Speed Control Servo (SCS from now on). Also check the condition of the vacuum hose connected to the plunger which goes thru the firewall to the SCS.
6. Check the condition of the hose from the SCS to the main vacuum source on the intake manafold.
7. Check the electrical plugs to the SCS (located near it). Take them apart, clean and reseat them. Before reconnecting them I suggest putting some dialectric grease on them to provide a moisture seal.
8. Check the connector to the Speed Sensor. The speed sensor is between the upper and lower speed cables just below the Break Vacuum booster, it sort of looks like a lolly pop. Take the connector apart, clean, add dialectric grease and reconnect.
9. Fuse 1 provides power to the SCA via the brake switch (light green with red hash marks) from the switch (light green) to the clutch switch (if not standard switch there should be a jumper plug in that connector) from there to the SCA.
10. Fuse 5 supplies voltage to the SCA via a white with pink stripe wire thru the connector on the steering column. (There are two sort of half moon connectors in that area when the SCA is installed. A truck without cruise control only has one) attached to the lower steeering column).
11. The other wires on the SCA go directly thru the firewall to the SCS.
So if all the above are good and you do indeed have all three brushes under the steering wheel you have three components left. The SCS, the SCA or the Speed sensor.
OK hope this helps you better than the first reply.
Good luck,
>-
Seabronc
New member
PS
Item 9 should read ( if not standard shift,........)>-
Item 9 should read ( if not standard shift,........)
>-grande_guerre
grande mondiale
thanks for breaking it down so i could understand. Sorry for any hassles. I'll try checking all these myself soon. Thanks!!
Seabronc
New member
No problem, in item 9 i mentioned a jumper. If you have automatic, the leads with the jumper are right next to crfescent shaped connectors.
Good luck,
>-
Good luck,
>-
