Electric Choke and HEI

[NavyChief]

Okay I have been scouring the boards but have not found the answer to the question (I probably missed it though and electrical is not my strong point):

I have a 250 straight six in a 1969 C10. I am getting ready to upgrade to an HEI and a Weber 32/26 w/ electric choke. Can I run both these off the same spot on the fuse panel (Ignition spot) or should they be ran from separate spots. I just figured I would run a line to the engine compartment and then split it to go to the HEI and choke.

Thoughts?

[marks1972]

howdy ho shipmate.
not sure about a tecnical answer however i would not do it.
when you change from points to a HEI you need to upgrade from the small resistor wire to a good 10g wire inorder to get your full volts to the HEI.
i would not add anything else to the line that might take some of that away.
when i first put in my HEI I didnt upgrade the wire and was not getting full volts. someone suggested i did and it was amaising at how much my engine came to life after getting the full dosage.

[54belair]

Im not sure of the current requirements of an HEI (or an electric choke) for that matter, but----I do know for sure that 18 ga. wire will handle 14 amps in an open air situation, all day long and 16 ga wire is good for 18 amps. The 10 ga. wire youre talking about is rated for 30 to 35 amps------You should Never need that kind of ampacity.

I have HEI on both my street rods and use the standard 16 ga wire that is part of the wiring harness I use----never had an issue.

[NavyChief]

Thanks that is what I figured. Now the issue is that I only have 1 free Ignition slot on the fuse panel so where to pull the other wire from?

[marks1972]

I found a blank terminal on the fuse block engine side that was empty and used it for my electric choke not sure what was originally there.

[Longhorn 70]

You could do what I am about to try. The HEI likes current. Add a relay. Run both from the relay that is wired from the junction block by the battery.

Wire from junction block to one side of the relay
wire from N.O. contact on the relay to HEI and Choke heater
Wire from ignition switch to one side of the relay coil
wire from opposite side of relay coil to ground.

I'm going to do this on Saturday (or sooner if the boss lets me). I'll let you know how it goes.

[NavyChief]

Longhorn 70 Let me know how that works and I will see. A little more than I am used to so I will have to read up and learn electrical!

[NavyChief]

Marks1972 do you have a pic or can you tell me where it is located? I am tempted to do the same.

[Longhorn 70]

After reading more on Edelbrock's website. I am going to change my plan. The wiring for the choke heater looks like it will work better if I have some kind of thermal control. I am now looking for a temp sensor that I can wire in series.

I'll add updates as they come but I don't want to make a wiring rat's nest.

[MrSector9]

Longhorn's setup would be the "proper" way to power the additional electronics, not saying that the other way is necessarily wrong or will not work, but with a relay is the correct way and not very expensive/difficult.

I do not see a need for a thermo switch inline for the carb choke heater with the exception of complicating the wiring, in real world application I cannot see if making that much of a difference.

In theory it does however as from what I understand you are attempting is once engine/choke reaches operating temp you can then cut the 12 volt signal running to the choke heater, the issue I see that would arise with this is then if the choke cools off enough to allow closure but engine is still warm you will run overly rich (I know this would be impossible) so in the end like I said I think it would just complicate wiring and then adding more failure points compared to just having it wired to the relay.

[NavyChief]

Longhorn sound sliek you know a lot more than me so please let me know how it goes and remember copying is the best form of flattery?!?!?

[Wrenchbender Ret]

I solder a 12 gauge wire to the pink wire in back of the ign. switch for the HEI. I use the fuse panel for the electric choke & put in an inline fuse about 7 1/2 amps. 16-18 gauge wire is good as it doesn't take much current.

[marks1972]

no problem shipmate.
as soon as i get home i will take one and post it.

[PanelDeland]

WELCOME!!!!



Look in the FAQ's truck related.There is a write up from member "shifty" that will allow you to connect from the firewall connector to the Ign. with a wire in the original spot on the firewall connector.Then you can use the terminal you have for the choke.



Here's the link to a great way to do an HEI conversion http://67-72chevytrucks.com/vboard/s...d.php?t=148346

[marks1972]

that is how i did my HEI

[NavyChief]

Once again the board comes through!!!! Thanks everyone. I know what I will be doing tomorrow night when I get home!

[VetteVet]

Wire it to the yellow wire on the fuse panel off the windshield wiper motor. It's a ley on power source with a fuse already in place and the wipers are rarely used and even when they are the fuse will handle both draws easily.

[magwakeenercew2jh]

Originally Posted by VetteVet

Wire it to the yellow wire on the fuse panel off the windshield wiper motor. It's a ley on power source with a fuse already in place and the wipers are rarely used and even when they are the fuse will handle both draws easily.

Was waiting for you to come in with that, Vette.

If you didn't, I was going to repeat exactly that suggestion. After all, I wired in mine like that when you told *me* to do the same thing. A perfect and tidy solution.

[Longhorn 70]

Sorry Chief, I wussed out and didn't get to it today. I had to do a "family date".

You know it will work without being heated. That is only to make the choke pull off quicker to lessen emissions. I have been driving mine for years without having it hooked up. I set the choke a bit lean and off I go.

When I do get it hooked up, I'll send pics. I still want to do the HEI portion of it.

VetteVet gave a good tip. You can use the Yellow wire. Just change it to a 14 gauge and go to the HEI and choke. The only thing I would do is measure the current accross that fuse while running the engine at higher RPM, wipers on and choke cold. Just so you don't get caugt in a sleet storm with a cold engine.

[VetteVet]

Thanks but I can't take credit for that one. I read it on another forum and it made good sense so I've been passing it along.
The first thing that comes to mind for a guy wiring one up is to piggyback off the ignition wire to the distributor or the coil. Even though it doesn't pull much amperage, less than 2 I believe, it might make a difference in the spark. I've read where some guys have not had any problems and I've read where others have had high rpm misses. If you wire it inline with the points coil it will be reduced by the coil resistance wire or the ballast resistor and the choke coil won't get a full 12 volts.

The ign-unfused spot on the fuse panel is a good spot but then you have to wire in a fuse and that is usually where we tap for the HEI distributor.

[cdowns]

i just replace the original dizzy wire( resistor wire) in the harness at the firwall plug with a 12ga wireand rewrap the harness for the factory stock look/// choke i run aa 12volt from the fuse box

[Longhorn 70]

I did the same many years ago but don't really want too much current going through the ignition switch. That is why I am going to install another point of failure, a relay.

[chiefcfd]

Welcome to the board Navy Chief. I'm just a few miles away across the boarder. Maybe we can get together sometimes.

[NavyChief]

Cool! Thanks everyone for the input.

chiefcfd... anytime! My truck is a work in progress so don't judge!

[jayman68]

I think the therm switch is to keep the choke open when you shut down the engine, then if you restart while the engine is still warm the choke will not be closed again.(Don't know if that would work)