Quote:
Originally Posted by bmartin9122
I agree with you. Regardless, whether or not the cable is the culprit, I still need to check that. It may be engaging the speedometer inside, but not some other electrical component related to the cruise control.
I know I have good vacuum. I checked both control wires, and I never got any voltage from either one. Hmmmmmm.....
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You have vacuum so check that one off. Make sure the servo isn't leaking.
If the Speedometer works the cables are connected good enough to spin the governor.
The transducer body needs to be well grounded. Usually the inner fender is a good ground.
There are actually only 4 wires in the whole cruise system.
12volts from the fuse panel to the brake pedal switch. PINK wire.
12volts from the brake pedal switch to the column switch. RED wire.
Two wires to the transducer from the column switch.
WHITE wire engage.
BROWN wire hold.
You should have power to the hold terminal any time the ignition is on. Fix that problem first.
The under dash cruise control power wiring is extremely short. It's a PINK wire that plugs into the front of the fuse box runs directly to the switch on your brake pedal. After the Pedal switch it goes to the steering column button via a RED wire. It's an add on harness so it probably does not mix with the main wiring harness.
When the switch is out, only the "hold" terminal should be powered. In this position you should have continuity from BROWN to RED at the switch harness under the dash. This is the idle or hold state.
When you push the stalk button all the way down, power is cut off to all wires. This kills the set-point. The way the terminals are located in the switch "hold" could be connected to "engage" but connecting these two wires doesn't do anything.
When you release the button the switch passes a point partway up where it energizes "engage" and "hold" at the same time. With the switch unplugged on the column you will have continuity on all 3 wires from the switch with the plunger partway between the bottom and top. This engages SET speed. It's imperative that all 3 positions work as designed.
There are some items that are internal to the cruise controller:
1. A low speed switch that opens below 35 mph to prevent cruise from engaging.
2. A mechanical governor driven off the speedo cable.
3. A variable vacuum orifice valve to control the cruise control throttle servo.
4. A solenoid coil that sets the speed by connecting (2) to (3), closes contacts to latch in "hold" power, and also control a vacuum dump valve. It's a very busy solenoid.
Leave the controller until last. If you can get power to "hold" and "engage" when you want it that's the hard part. It's then narrowed down to the transducer/controller. You can find a known good one and swap. From the wiring diagrams, it appears the transducer/controller body needs to be grounded to work.
This is an edited post from an F body board on the early cruise control setups.