Thread: Dual Quad Elec Choke Question

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Running dual, synch'd Holley 390cfm carbs, P/N 8007. Electric chokes, each with a hot and ground plug.

Split the hot wire to the choke, ran it to each hot lead on each carb. Grounded the carbs to the block. The hot wires have power when neither of them are hooked to the carbs, but they both lose power when one (or both) of them are hooked up.

What did I miss?

> Does the choke open the the choke plates?

The chokes do not function, that I can see.

check voltage drop on the hot wire. you might be losing it when it's hooked up. ie not enough current for the load. where are you getting power from? you should take it from stator wire on alternator so it's only hot when running. also make sure of the 2 connections on choke power is power & ground is ground.

Thanks, all. Fast responses!

The power is coming off the alternator, and before the split in the wire there is 12V. There is no, I mean zero, power at either end of the hot lead (after the split) when either side is hooked up to a choke. There is just under 12V at both ends when neither end is hooked up.

Denny, I'll scrap the whole thing and try it your way. I'm still curious as to why I'm not getting any power when one or the other is hooked up, though; it kinda makes me uneasy.

your dropping voltage across the circuit.backprobe the wire from the choke back to where you get source voltage.it sounds like you got high resistance in the circuit. use an ohmeter to check circuit.all cars came with power to choke off of the alt.not all had full 12v to chokes.some used pulsed volts ie the voltage would be on and off while running. if you have a switched power source to the choke you feed voltage to it whenever key is on.so if you don't start the car but leave the key on you heat up the choke or if car stalls and key is on the choke will open anyway.result cold car warm chokes. that's why it's better to use alt.

Aside from the potential voltage problems that look to be well covered, you may want to think about using both chokes.

The dual quad Corvettes of the early 60's had thermostatically controlled chokes that derived their heat from an exhaust manifold heat stove.
The rear carb was the only one with a choke.
Corvette owners that I've talked to tell me it works fine that way.

That said, I ran a pair of dual quads on a 462" Buick and had one manual choke cable controlling both.
It worked very well.

Never got around to trying it with only one manual choke since it did work ok and at the time never found anyone who'd run dual quads who had double/single carb choke experience.


To shoot off on a tangent a touch, I swapped to a single 600 Holley with diaphragm controlled secondaries and elec choke.
It worked fine, but with the hood sides off the 32 roadster if you parked the fully warm engine on a cold day - 40's and below - the choke would kick in whether that car had sat for hours or just a couple of minutes.

Same situation with a single elec choke 750 Carter, the choke would not go on unless the engine had cooled off considerably and the choke was actually required.

Once the louvered hood sides were on, either carb's choke would operate as they should.

I always run my electric choke to a spot on the fuse box marked "ign"...has always worked fine...