Ok, for those that remember, I am doing a ground up build. Which includes all custome wiring. Well, I had my 12+ feed to the HEI ran, and then I needed a switch feed for the alt and the choke, so I t-tapped off of the HEI 12+ feed. A nice 12ga wire. Well, the car ran fine when it was warm outside. Started right up like a killing machine, but I had a problem of when the car was warmed up and I turned it off, it wouldnt turn back on! Trying to find the problem, I checked the realy box I built and found that the terminal the HEI feed was on was too hot to touch! I let it cool down and the car fired up again. I assumed that the alt and choke was pulling too much because it was getting 7v instead of 12v at the HEI.

Well, I got a new battery (was using a loaner) and now it's freezing outside. I go to fire up the beast and it just will not start. I havent touched a thing since last time I fired it up, but it just would not start. After draining the new battery trying to fire up the car, I pulled off the alt switch wire and put the charger on the batt, but it didnt help. I put the alt wire back on and pulled the choke 12+ wire off and the car fired right up (then died because of no choke).

I have been meaning to put the alt and choke on seperated feed from the HEI to fix this, but how much does the damn choke really draw? Any ideas? I wouldnt think a small device like that would cause such a big problem as preventing the HEI from getting enough juice.

I expect I am the only one that has ever had this problem, and I will be fixing it, but just wanted to know if anyone knew.

 

The choke heater is not unlike your cigarette lighter in it's electrical demands. I would wire it the same, dedicated circuit with 16 gauge wire & 20 amp fuse.

 

Your electric choke is basically a short in the circuit. If you have a voltmeter you can measure the voltage at the HEI with the choke plugged in and then without. Then check the voltage at the choke. You also my want to check all of your grounds. Especially at the choke and from the motor to the frame. Bad grounds cause major voltage drops. But definately get it its own circuit. Good luck with your troubleshooting! Merry Christmas!

 

You really shouldn't use the HEI power wire to run ANYTHING else. The HEI doesn't draw that much on AVERAGE but it's draw has a lot of "peaks and valleys" as the coil alternately charges and fires. Makes for a bad power source for anything else that requires constant voltage. Not sure of whether this would account for your situation but it's bad practice just on general principle.

A choke coil doesn't draw much- coupla amps tops, more when it's cold, less when it's hot. That's why you often see the wire going to an electric choke being small gage- 16 or so. Like was said above- sort of like a cigarette lighter, although I doubt it's even that powerful.

 

All the grounds are fine, plenty of them too. I will be running the choke on seperate circuit either way. Thanks for the response.

 

Just thought it this through. You had the choke wired in series with the HEI power. This would make the two devices share the 12vdc being supplied. Meaning neither device was actually getting the full 12vdc it required to operate. As a rule when wired in series Voltage divides, and when in Parallel Current divides. But probably too much info for you anywho. Good luck!

 

i dont have the ran in series, the choke and alt are t-tapped from the main feed to hei.