Got a SBC with HEI dizzy and Edelbrock 650 CFM carb with electric choke, I want to get 12 Volt power wire from HEI Dizzy SPLICED into wire that goes to side Dizzy marked BATT not Tac-- it will be switched operated when ignition is turned on--- Am I correct on doing this I DO NOT want to go from fuse panel and drill hole thru firewall-- I want to know will this be correct -- Thanks
Not a great idea to attach anything to Coil wire going to distributor. It needs to come from ignition switch source not connected to anything ***ociated with the distributor.
Well, it'll work--but as the others said, not the best idea. Full voltage to the distb. is always preferable with no splices anywhere. An E choke doesn't take a welding cable, a small 14-16 ga. wire will do it, 12 ga. if you're worried. That's about an 1/8" hole.
Or just snake it through an existing hole with some other wire. I usually run mine from the ignition switch to the choke. There are always some wire bundles already going though the firewall and there is usually enough room to get just one more wire through there.
Really should never do this , if choke heater was to short, your dead in the water . The choke should be wired to stator side of Alt wiring .
Sneaking over to another board I got this That goes along with Dethrowdave's post. Factory GM is hooked to a relay that is triggered off the Field circuit of the alternator . Doc being the gent who answered the question. Doc here, imp: NEVER run any "Extra wires" from the coil + circuit of any coil..ESPECIALLY a high draw item, such as a choke heating element! This Circuit is Dedicated AND protected to run the coil circuit ONLY..Coils can draw up to 20 amps, and Performance Coils can draw as much as 48 amps Full load draw.. IF you run a choke element, (and these can draw as much as 15 to 20 amps) you end up taxing the coil circuit and "load sharing" between the two devices..the element can act as would a ballast resistor on a remote coil , dropping voltage under load to 6 to 9 volts..On an HEI, this is not going to run..Or if it does, perform like "**** in a can.." The result is heating..the wire will heat up from improper gauge, (heat is current doing NO useful work) for the new load imposed..and BOTH circuits will suffer..the Choke won't open AND that $600 performance ignition won't even perform as well as a stocker.. GM , traditionally , uses a Choke Heater RELAY from the Field circuit ( the brown wire going to the idiot lamp from the alternator) to fire a relay coil, whose contacts provide power from the battery direct Via a fuse link or maxi fuse, to the heater element.. The relay ONLY energizes when the alternator has output..(engine MUST be running..) before the element gets power to heat up..In this configuration, If you are listening to the radio in the "Run" or ACC positions while working on the car..(and we ALL do that..) , or have the key on, while loading the car, belting the kids in, s****ing ice from the windows..the Choke won't open on a DEAD cold engine..defeating it's purpose.. After the engine starts, it takes about 3 minutes to heat up, then bump the throttle to slip the mechanical detents, and it should return to full open choke, and normal curb idle. Another little added bennie..when the alternator diodes start to fail..that relay will "Buzz" like a "mini shaver" from the raw AC, telling you BEFORE you have morning sickness (dead battery's every morning) that service is in order..
Easy Peasy!! [treed by 1 minute] Use a relay in the engine bay from the Alternator to the electric choke [no hole in the firewall is needed] On the Relay Post # 30 connects to the alternator charge wire [to the battery] Post # 87 connects to the electric choke Post # 87a is not used Post # 86 is spliced into the idiot light wire on the Alternator Post # 85 connects to ground [Note post #86 and #85 can be connected either way, but if you use a "diode protected relay" #85 is always ground, So it is good practice to get this right even though the schematic has it the other way round] I also prefer the electric choke to only be activated with the engine running, but this method requires an ignition switched 12v source. On the Relay Post # 30 connects to a 12v "switched" source [fuse box accessory or ignition switch] Post # 87 is not used Post # 87a connects to the electric choke Post # 86 is bridged to Post # 30 so it also becomes switched Post # 85 connects to ground via the oil light sender [splice this into the oil light wire] With this ^^^^ Ignition Off and the relay is dead Ignition On and the engine is not running the relay switches to post # 87 so the choke is dead Ignition On and the engine is running the relay switches to post # 87A so the choke is activated I have this in my 57 Chevy and we also have a priming fuel pump connected to Post # 87 on the relay. Switch it on and the pump primes. Start the engine and the pump switches off and the choke is activated.
Cool beans, that is a rather simple setup that actually works as intended Thanks for putting that together.
I have got to ask a gloriously stupid question here. How do the wires get from inside the car to the engine bay? I know that late model cars have a plug on the firewall but what about the rest of the cars that we drive? You all are taking something bone head simple and making it excessively complicated. Relays and diodes and voltage return lines. Oh my. Just run a switched hot wire. if there is no place to get from the switch to the carb make a way, hell drop your wire out through the toe board if you have no other place. No one is ever gonna see it at the car show.
Not sure where some of you are getting your figures from but a typical ignition coil is about 3 ohms and the an Edelbrock electric choke is 10 ohms, that's a current draw of 4 Amps and 1.2 amps respectively. The choke takes less power than a single brake light bulb. If you are worried about a dead short taking out the ignition fuse then use a 5A inline fuse to the choke.
I guess this is the world we live in--let's get a supercomputer, add 49 relays, 32 wires, bluetooth, greentooth, notooth, 2 laptops and have it dyno'd. Then run one wire to the choke.
As a temporary fix I ran a wire from the + terminal post from the coil to the carb choke, so no splices. Works fine, as the wire gauge is way over the top for coil power alone. I will get around to rewire it one day..... honest I will.
Don’t need no stinkn’ relay. That little German air cooled car that they sold more millions of than a Model T had a wire from the choke straight down to the hot side of the coil and had a double clip to attach it. Never affected the running of any of them that I had.
I never measured the amp draw of an electric choke, but I think those figures in the post above of 15 - 20 amps is way over estimating. They really only draw much at all when heating up, and once heated up the current draw drops way off to a negligible amount, not enough to affect voltage to the coil. But if it really bothers you, use a relay to grab the main current from the starter solenoid where the main battery cable attaches, then tap off the coil + terminal to trigger the relay when the ignition switch is On, and you can use an inline fuse to protect that circuit. A relay draws only a very small current to hold it in the engaged position.
This reminds me of a buddy's Nova he bought and asked me to help him get it running. Some joker that owned it had issues with the alternator not charging the battery, and added a bunch of compact relays, and wiring to the firewall. After trying to follow the charge wire off the alternator all over the engine bay, and trying to figure out why all the relays were added, I got irritated and just started cutting everything off and ripping all the relays and wiring out. Then traced the large red wire under the radiator support, and across the firewall, and around the driver's side, only to find the end for the battery never connected to the other end from the alternator! Cut all that out also, and wired the alternator to the battery terminal wire, and fired the car up. It charged and ran fine, and everything worked. Still have no idea what those extra 5 relays, and abundant wiring was doing? Why do guys insist on complicating a system that worked perfectly for years? Just do it like the factories did it.
You guys are way too complicated. I have a 3 pin oil pressure switch. One pin is to ground and opens when pressure comes up to turn off the idiot light. The other 2 pins are normally open and close when the oil pressure comes up. When the switch sees pressure the choke circuit comes on. With the key on and engine off, no current flows and choke isn't heating. .bjb
Sometimes the old ways are best.... LOL Before the advent of fancy-shmancy alternators with internal regulators, getting electric choke power was easy. If you had a generator, simply tap off the 'A' terminal at your regulator or at the generator end of that wire, whichever is the shorter path. Alternators were just as easy. Most had a 'Stator' terminal (and in the case of a Ford alternator if you wired it without an idiot light, it was unused), simply connect here and run to the choke. This connection outputs about 9 volts, enough to run the choke element. No relay needed, no connection needed to the ignition switch either. Power is only present at these points when the charging system is working, so no current drain when the motor is stopped. This is correct, they really don't draw all that much when 'cold' and even less once up to temp.
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