Idle Stop Solenoid

[Brad H.]

I have a 69 300/350 with automatic and AC. The car did not have an idle stop solenoid wired from the AC when I bought it and the wiring looked original. Would this car have had the idle stop solenoid mounted on the carb? Some of the later ones had vacuum plumbed from the carb to it as well. I can't find a wiring diagram that shows it specifically and Lectric Limited catalog shows a jumper harness from the AC compressor wire to the solenoid, but only shows it for manual trans cars.

Anyone have any photos of this thing on a 69 auto? I'm pretty sure it had one, but maybe I'm mistaken....
Thanks for any help,
Brad Hood

[William C.]

Re: Idle Stop Solenoid

The Idle stop solenoid was used in '69 to eliminate run-on when the key was shut off on Manual trans cars. I don't believe it was used on auto trans cars in that year. That was the first year of use, and it was put in place very late prior to model change. I was responsible for the wiring harness assembly process for Chevy engine wiring at that time and we had to re-engineer the process and start the new builds over a period of about four days (including a saturday and sunday) At least that is what I remember, but it was a long time ago...

[Jim T.]

Re: Idle Stop Solenoid

My 70 350/300 turbo 400 with air conditioning did not have did not have this solenoid on the carburator. It does have a solenoid that can control idle speed and this solenoid is mounded on the intake manifold on the right side.

1971 was the first year for a solenoid unit attached to the carb that controlled idle speed and also controlled vacuum to the vacuum advance.
The Spring 2009 issue of the Corvette Restorer has a very good article on the solenoid by Jack Humphrey.

[Jeffrey S.]

Re: Idle Stop Solenoid

Brad:
My '69 350/300 auto a/c car does not have the solenoid you refer to or any wiring from the original harness for one. AIM indicates that L36 and L46 w/M20 and M21 had it (page C5 in C60 section).
Jeff

[Brad H.]

Re: Idle Stop Solenoid

Thanks to everyone for the replies. Mr. Clupper, when was the idle solenoid installed to control idle speed for air conditioning activation on idle. I believe it was around 1971. Is that correct?
Thanks again,
Brad Hood

[William C.]

Re: Idle Stop Solenoid

I believe that is correct, but I had moved onto another position by that time, so I had no direct involvement, but the function also changed over the years, some years it was an idle speed kickup for air conditioned cars, rather than just a device to eliminate run-on.

[John N.]

Re: Idle Stop Solenoid

My 1969 350HP, air conditioned and four speed car has the solenoid, produced 3/17/69, serial # 19320, original owner, Five Star Bowtie & Duntov. By memory its AC related. Edit: After rereading the above post and not trusting my memory, Sally and I fired the 1969 up and it definitely is a idle speed kickup for A/C.
Regards

[Kurt B.]

Re: Idle Stop Solenoid

Bill Clupper,
Should a small block 68 with A/C and 4 speed transmission have such a solenoid?
Thank you,
Kurt
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