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Took a ride on the highway today and used the cruise control for the first time. It worked great to the rest area but when I got back on the highway it wouldn't engage for a while then it did. And it did the same thing on the way home.
Anyone experience this or have any thoughts?
Pat
I always found my 78 cruise control temperamental. Had the transducer rebuilt but it still operated with a mind of its own. I recall that it would surge...then drift back down to speed setting. I even used graphite on the cable...then just quit using it.
I always found my 78 cruise control temperamental. Had the transducer rebuilt but it still operated with a mind of its own. I recall that it would surge...then drift back down to speed setting. I even used graphite on the cable...then just quit using it.
Thanks,
when mine does work it works fine I just have a problem getting it to engage
Took a ride on the highway today and used the cruise control for the first time. It worked great to the rest area but when I got back on the highway it wouldn't engage for a while then it did. And it did the same thing on the way home.
Anyone experience this or have any thoughts?
Pat
Sounds to me that your Transducers LOW SPEED contacts may not be closing at or above 30 MPH.
Here is a TEST to determine if your transducer is receiving a signal from the cruise switch, and that the solenoid is actually energizing.
You will first have to remove the spring clip and rod from the Carburetor (RED X). Only for testing so the engine will not rev when Servo pulls in.
Then remove the 2 wire connector from the Transducer and rotate it so that the White wire lands at the HOLD terminal of the Transducer.
Brown wire will not be connected to ANY terminal...
This bypasses the LOW SPEED transducer contacts.
Start Engine, have someone press the cruise switch, Transducers Solenoid MUST energize and the Servo starts pulling in.
Release switch Servo should return to its home position.
Do this test many times just to see if the operation is consistent.
Hunt:
You have Port A & Port B on the Transducer
Follow Port B vacuum line back to the intake 3 way fitting.
Make sure that hose is not kinked or internally blocked or partially blocked in any way.
Sounds to me that your Transducers LOW SPEED contacts may not be closing at or above 30 MPH.
Here is a TEST to determine if your transducer is receiving a signal from the cruise switch, and that the solenoid is actually energizing.
You will first have to remove the spring clip and rod from the Carburetor (RED X). Only for testing so the engine will not rev when Servo pulls in.
Then remove the 2 wire connector from the Transducer and rotate it so that the White wire lands at the HOLD terminal of the Transducer.
Brown wire will not be connected to ANY terminal...
This bypasses the LOW SPEED transducer contacts.
Start Engine, have someone press the cruise switch, Transducers Solenoid MUST energize and the Servo starts pulling in.
Release switch Servo should return to its home position.
Do this test many times just to see if the operation is consistent.
Hunt:
You have Port A & Port B on the Transducer
Follow Port B vacuum line back to the intake 3 way fitting.
Make sure that hose is not kinked or internally blocked or partially blocked in any way.
Thanks for the info will look into what you said. I forgot to mention that at the times when it's not engaging when I push the button to try and set it that has an affect on the tach it moves
Pat
I had a similar issue with my 1977 cruise control. I replaced the transducer with no effect. I ended up replacing the cruise control harness and switch inside the steering column. Worked great thereafter.
One more thing to check: I discovered that the brake pedal switch was set so even the slightest movement of the brake would disengage cruise. When I stepped on the brake and then let go, brake lights would go off but it wouldn’t return all the way back up so the cruise wouldn’t re engage. Didn’t affect the brake lights because they are two separate sets of contacts on the same plunger.
I could prove this was the problem pulling up on the brake pedal, and then cruise would work again.
One more thing to check: I discovered that the brake pedal switch was set so even the slightest movement of the brake would disengage cruise. Didn’t affect the brake lights, as they are two separate sets of contacts on the same switch.
I could prove this was the problem pulling up on the brake pedal, and then cruise would work.
78 Cruise Control
