JohnMR

I’m in the process of finishing up the engine bay on my 69 Cutlass. I’ve got an extra part that I’m not sure what it is. It’s some sort of electrical switch with a contact plunger on the end. Where does this thing go? Trunk light? Hood light? Brake switch? I’d love to know where this thing goes!

oldcutlass

It looks like an idle stop that is mounted on the carb.

redoldsman

I agree. That would be a solenoid, not a switch. Hook it up to 12 volts and see if actuates.

joe_padavano

So you have a 2bbl carb. Installation and adjustment is shown on Page 6M-74 of your Chassis Service Manual.

oddball

FWIW, those are useful on all A/C cars to kick up the idle when A/C engaged. New ones usually run around $100. Mounting varies from carb to carb, of course.

JohnMR

Got it. It was on page 6M-26. Makes total sense now. That also explains the extra wire in the engine bay that I had no clue where it went. Won't be needing that option for a few months seeing as it's 20 degrees outside, but I'll install it anyway just to finish her off.

joe_padavano

Doh! I should have said FIGURE 6M-74, which is on page 6M-26. Sorry about that. And to clarify, while some cars DID use an idle up solenoid to increase RPMs for A/C use, that is NOT the case here. This is an anti-dieseling solenoid that allows the throttle to close a little more than normal when you turn the key off so the engine doesn't run on. It was used on both A/C and non-A/C cars with 2bbl in 1969.

JohnMR

Interesting. I did notice on the wiring diagram that the solenoid went to “anti dieseling” and wondered what that was about. It wasn’t very specific. So thanks for the validity. I think the solenoid is dead as it does nothing with power applied. I don’t have any issue with diesling so I’m not gonna worry about it for now. If I have any issue in the future, I’ll know what part to replace. Thanks again.

tru-blue 442

Make sure the part is grounded or it won't work.