Wiring electric choke

I'm at the point of wiring my electric choke and I am an amateur at electrics. What I need to know the easiest and simplist underhood source for juice. My Commando has a 304 with HEI if that makes any difference. Explain it as if you were talking to a child cause when it comes to anything electrical that is what I am.Thanks for your imput.

 

What carb are we talking about and are you using a fuse block?

 

I'll have a look at my 73, been so long I can't remember where I wired it in.

 

I'm running an Edelbrock 500 cfm carb and the Jeep has no fuse block.

 

Edelbrock recommends a 20 amp fuse protected circuit (which is quite a bit) so it is not recommended to hook it to the ignition coil PLUS terminal. Without knowing what other modifications you have, my only recommendation would be a separate wire from the ignition switch directly to the choke. Ignition power to choke in the "ON" position only.

 

Sorry I forgot that a 10ga wire is recommended for this 20 amp circuit because it is hot (12-14VDC) continuously during operation.

 

Again I want an underhood source so are we talking coming off the starter solenoid or another location? And more specifically what connector on what power source. Remember I am a total noob with auto electrics. Also I'm running an HEI so coil is not an option, right? Thanks for all your responses, Bob

 

I suggest you use a wire from the solenoid to a relay. Then control the relay with power from the ignition.

http://www.parts-express.com/12-vdc...relay-spdt-30-40a-with-metal-bracket--330-079
http://www.parts-express.com/12-vdc-5-pin-relay-socket-for-bosch-type-relay--330-075

Walt is right that 20A is quite a lot to tap off of an existing circuit. So you'll need to create a circuit that turns on when the ignition is on. I can't believe that the choke coil dissipates 20A constantly - that's 4 60W light bulbs of heat coming from the choke cover. Darn hot. Painfully, meltingly hot.

Ideally you would also install a oil pressure switch so that the choke only starts to open once the engine is running. A Standard PS135 works for this. Lots of info on electric choke control for Holleys that shockingly would also work on an Edelbrock.

https://www.rockauto.com/catalog/moreinfo.php?pk=44184&jnid=2&jpid=0
https://www.google.com/search?q=holley+electric+choke+oil+pressure+switch&ie=utf-8&oe=utf-8

 

I also forgot to say I'm running an electric fuel pump which I hopefully wired correctly to a low oil pressure safety switch in case of an accident or rollover including a relay and the instructions said I could wire a switch into the circuit. The relay has one prong that I didn't need unless I used a switch to override the pressure switch to run the fuel pump to get fuel to the carb before oil pressure is high enough to power the pump. Is there a way to use this set up to power the choke ?

 

Without a circutit diagram of the switch, it's sort of hard to tell if it would work or not. A part # would help. Then again, we all like VOM's and test lights. You also have people like Timgr and Walt Couch that know their way around electrical things, there also seems to be many people that know computers, machining, woodworking, welding, language, geology, chemestry, etc.
A good place to be a member of.

 

That relay that has nothing on one prong is probably battery hot when the relay is not energized. Once the OP comes up and the relay is energized then this empty prong goes dead-(no power) so no you wouldn't be able to use it for your choke. If you have not run the engine since installing that electric fuel pump, you may find you will have to install that override switch you was talking about.

 

Usually electric fuel pumps with an oil pressure switch are wired so that the fuel pump is always energized when the starter is running. Then once the engine starts, the oil pressure switch takes over to keep the pump running. If wired this way, it may take a little cranking to start, but fuel will eventually get to the carburetor.

As Walt points out, the extra prong on the relay likely has the opposite performance from what you want for your choke.

 

The neighbor kid wired his electric choke directly to the battery, wondered why his battery was always dead. I wonder if I would have any fun if I didn't have the neighbor kids to entertain me.

 

So back to the original question. where would be the easiest place to wire up my choke from. Tell me exactly where to connect the positive choke wire to get power to the choke.

 

I'm in agreement with Tim...20 amp sounds like a lot for a choke circuit. In fact, I've installed many Edelbrock and Holley carbs and never used a wire that heavy. Both brands supply 16 gauge wire for hooking up power and ground for electric choke.
I can't tell you EXACTLY where to hook up the choke on your particular vehicle, just that you need a 12 volt switched power source...don't hook up an electric choke to the coil, it'll draw enough power that it can reduce coil output.

 

I hooked mine up to a switched 12 volt power source. In my case that was the ACC post on the starter switch. I used a generic 1970 or so cj5 replacement switch when I wired my 2a. No fuse.

This may help or not.
http://www.jeepforum.com/forum/f8/ignition-switch-diagram-1441717/

 

We've given you lots of pointers to previous in-depth discussions of how to do this. Sounds like you don't want to read the old posts or think/learn about what you are trying to do.

"I suggest you use a wire from the solenoid to a relay. Then control the relay with power from the ignition." The link that 47v6 gave you shows where to get the relay power from the ignition switch.

Here's another option, if you can't figure out what to do electrically -
https://www.google.com/search?q=edelbrock+manual+choke+conversion+kit&ie=utf-8&oe=utf-8

 

Personally, I always run an electric choke off the switched alternator terminal (#2 on a GM SI series alternator). NOT the lead to the battery and NOT the thin wire that triggers charging/dash light. If the connection is not switched by the ignition key, you will have a dead battery. It should be 12ga wire and fused for 20 amps. I have tied them to the HEI's power lead input and had it work fine too, but have encountered an ignition stumble on high powered engines that did not like sharing HEI coil power with an electric choke.

I still prefer my manual chokes on my daily travelers, hate to load the charging system with a constant 20 amp draw that really is useless once the engine is fully warm.