Power for electric choke

[Scott Wayne]

Hey y’all I just bought a 83 C20 and it’s got an edelbrock 1406 carb with an electric choke. I didn’t realize until I had already had it a few days that the choke doesn’t have power hooked up. I’ve been doing research on where to get power from, some people suggested the oil pressure switch but I don’t see one installed. There’s an opening in the fuse panel in the cab labeled “choke” but there are no female tabs to hold a fuse.

So basically my question is how else can I safely get power to the choke?

[bd]

Connect the choke heater wire to one of the IGN cavities in the fusebox through a 2-prong non-grounding oil pressure switch (OPS).  The OPS (image) can be threaded into one of the engine oil galley ports either at the back of the intake manifold next to the distributor or down adjacent to the oil filter.  The OPS ensures that the choke doesn't open up with the ignition switched ON unless the engine is running too.

[Scott Wayne]

I don’t believe this is a stock intake manifold but I’ll post two pictures. Second is a thread hole above the oil filter, is that for an oil pressure switch? Sorry I’m so new to this.

https://imgur.com/a/DnfQ7PN

[Scott Wayne]

Another thought I had was to use an “add a circuit” wire on a 12v keyed ignition fuse that’s already in the panel, as I have no empty slots for a new circuit. Could this work?

[VileZambonie]

He's not saying in the intake manifold, he's saying behind it, near the distributor.

[bd]

He's not saying in the intake manifold, he's saying behind it, near the distributor.

This ^^^^^, but it appears there is an oil pressure gauge sender occupying that location already.  To plumb the OPS and gauge sender to share the same galley would require a tee fitting and ~2" x 1/8" NPT nipple.  The oil galley tap down near the oil filter should be 1/4" NPT and located just forward from the filter - not the threaded hole that you pictured above the filter.

Post a clear, full-frame pic of the fusebox.

[Scott Wayne]

Thank you for the help with this, I don’t really know anyone that can help me so I have to rely on what I can find on the internet.

https://imgur.com/a/MRsn2bL

That’s the best pic I could get with the brake assist thing in the way

[bd]

Use either of the two ignition power taps pictured.  Both are protected by the 20-amp fuse positioned directly below them.

[Scott Wayne]

Thank you bd!! I’ll get started on this ASAP!

[bd]

If you want the power wire to integrate nicely with the factory fusebox connector and lock in place, pick up an American Autowire 500429 ATO power tap kit.  You can also acquire a Standard Motor Products S-939 molded connector for the OPS if you like.  Neither are necessary but they make for a cleaner installation.

[Scott Wayne]

I thought I could go straight from the fuse box to the choke without an OPS?

[bd]

You could, BUT THEN the choke would begin to open as soon as the ignition is switched on.  Suppose it is icy weather.  You switch the ignition on and crank the engine to start.  It doesn't start right away, so you crank the engine repeatedly.  Finally, the engine fires but then dies almost immediately.  You crank it some more and it starts but you find that it is a struggle to keep it running and it backfires through the carburetor.  Why?  Because the whole time you were cranking the engine, from the moment you switched the ignition on, the choke was heating up and opening.  By the time the engine started the choke was fully open, so the engine wasn't getting sufficient fuel to run efficiently.  Had you installed the OPS, the choke wouldn't begin to open until after the engine was running. 

Essentially, installing a choke OPS provides improved cold weather starting and drivability.  It is in your best interest.

[Scott Wayne]

Then I’m back to square one because I don’t have an OPS

[Scott Wayne]

https://imgur.com/a/MMiNdGy

Here’s a better pic, there is no hole forward of the oil filter, just the freeze plug.

[VileZambonie]

Looks like some engine degreaser will help