This morning I hooked up the electric choke on my replacement Holley. I wanted to check the current readings and this is what I found. Choke hooked up to bottom of ballast resistor reads 11 VDC. Top of ballast resistor reads 5.22 VDC. Battery reads 12.2 VDC. Are these readings normal? 5.22 does not seem like enough coming out of ballast resistor. Any help appreciated.

 

Depends on if the ignition points were closed or open. From your readings, it would indicate the points were closed, therefore the coil is drawing current, and the reason for the voltage drop across the resistor. If the vehicle was running, you would see closer to 14 volts at the battery (and slightly lower at the input to the resistor due to the voltage drop through the wiring, ignition switch, etc. caused by any item that is drawing current - the higher the current draw, the lower the voltage available - in other words, don't turn on the headlights when starting the engine). The coil side of the ballast resistor would bounce between the input side reading (close to 14V) when the points are open, and be probably in the 6V range each time the points close (depends on the ballast resistor resistance vs, the coil impedance).

Note that when the starting circuit is engaged, the ballast resistor is bypassed via a contact in the starter solenoid, which then feeds full battery voltage to the ignition coil. Since the engine is not running, the generator/alternator is not producing any significant output, and the starter draw is significant (can pull the battery voltage down to the 10V or lower range), this ballast resistor bypass is an important feature in ensuring sufficient voltage is supplied to the coil.

From a purely performance viewpoint, the ballast resistor feed wire is not the best place for hooking up an electric choke (which is a constant current draw, and will lower the available voltage to the coil). It may or may not affect your ignition output. In most cases it will not, but if your ignition is marginial to begin with-----------.

I am not a big fan of electric chokes, but understand the usage in some appications. Just note that a drive followed by a short stop, and then an attempted refire can cause choke related flooding. The engine is hot from the drive, but the choke cools off much more rapidly during the short stop, and resets itself in the choke closed position - resulting in a flooded engine. Just be aware of this possiblility, and the possible need to floor the pedal (to clear the engine and open the choke).

Plasticman

 

I recently checked the voltage on one of my cars and came up with the following numbers. This is a car that starts easily and runs perfectly.

Battery 12.0 volts
Resistor input 11.7 volts
Resistor out 5.4 volts

Factory specs are 5 to 7 volts.

 

I'm running a 550 CFM 2 BBL for the middle carb (primary) of my 435/Tri power BB, with the holley electric choke...

If you wire the electric choke to the 12V input side (12V when key is turned on) of the ballast resistor you will not have a problem. I also use the same point (12V into the ballast res.) to power on my MSD 6A box. The other end of the resistor goes no where (but I like the way ot looks on the firewall so I installed a wire to the output that is not connected to anything) as the ballast res is not needed with the MSD System - I also have fused the 12v lead to the choke with a 3amp fuse to be safe.

However before I got the MSD System, I was running a dual point mallory distributor which was wired to the coil thru the other end of the ballast resistor (Output-lower voltage side) and had no issues whatsoever with the electric choke or the ignition coil. Car ran fine

 

Hey it's winter so we all need a choke - except here in FL!!!!

Run a 16 gauge wire to a switched source at the fusebox. Make sure it is after the fuse. If you still need more juice a separate relay will be required.

 

Probably better to check resistance with an ohm meter. Should be about 1.8 ohms.

 

I found I never needed a choke.

Always wired it open,and just compensated by a couple shots of the accel pump prior to start, even at -40F in Montana in January.

Only drawback was had to let the car warm up for a few minutes prior to driving and do your own fast idle thing with your foot for a couple minutes.

Doug