Topic: 70 428CJ w/AC - Throttle solenoid wiring question

[wjgrnp]

Thanks for the replies.
My understanding is that for a 70 auto with A/C the solenoid is simply there to bump up the idle speed when the A/C is operating.
Mine is energised as soon as the key is moved to on position regardless of A/C setting.
Any ideas?
Thanks

[midlife]

Based upon the factory descriptions and how the wiring works, that solenoid line is energized when the key is in the RUN position at all times and is independent of the AC.

[sah62]

Thanks for the replies.
My understanding is that for a 70 auto with A/C the solenoid is simply there to bump up the idle speed when the A/C is operating.
Mine is energised as soon as the key is moved to on position regardless of A/C setting.
Any ideas?
Thanks

If you got that info from my 428 registry web site it could be that I need to change my carb ID page based on the research folks have presented here. I've read through this thread and will change the page as soon as I can.

[cobrajet_carl]

Thanks for the replies.
My understanding is that for a 70 auto with A/C the solenoid is simply there to bump up the idle speed when the A/C is operating.
Mine is energised as soon as the key is moved to on position regardless of A/C setting.
Any ideas?
Thanks

It was believed that 428CJ cars with A/C would run hotter and therefore be more prone to dieseling when shut off. That is why the A/C cars have the solenoid.

[wjgrnp]

Thanks for all the feedback.
I have now treated the solenoid as an idle speed solenoid to halt running-on.
I have set the solenoid at about 800 rpm and backed off the idle screw to about 500.
What I did find was that the solenoid does not have the strength to push but will hold. So by holding the accelerator pedal down the ram is activated to its set position and then when you release the accelerator it settles back to the activated position.
Thanks to all for solving the mystery.
Regards
Ward

[tobkob]

That is the way they were designed to work. You always had to depress accelerator enough to let the solenoid to activate. There should be enough travel in the plunger to completely close the throttle plates.
TOB