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1973 Chevy Nova Ignition System

I am wanting to replace the ignition system in my nova and was trying to find any source that would help me map this out from the ignition switch to under the hood. Any information would be very helpful.


You want to replace the ignition switch? Replace the points with a Pertronix breakerless ignition? Replace points, rotor, condensor?

You need to be more specific. What is the problem? If you want a schematic perhaps you can get a Haynes manual for the car.

I want to replace the switch and just in case the wiring as well. This car has been sitting for a while and would like to have peace of mind knowing that systemically the ignition system wont give me too many problems

Your entire “ignition system” is in the distributor. Replace the distributor, cap, rotor, wires and plugs for less than $200 and you will have an entirely new ignition system. The switch is part of the ignition but it is rarely problematic. Maybe you could give this forum some insight into what specific problem you wish to avoid. Uncle Turbo’s post seemed very succinct. But obviously you have some baggage regarding ignition problems. Lay it on the line.

My favorite method is to determine the problem and only replace (spend money) on necessary parts.

Rod Knox thanks that’s what i was wanting to know/ Sorry about not going more into detail. I have done basic repairs like replacing the distributor wires and cap but not the whole distributor. Now that i know what it entails i feel more comfortable as i have the Chiltons manual and i think i can work from there.

The points ignition is high maintenance and replacing the entire distributor with a “HEI” unit used from 1975 until 1981 at least will greatly improve things, improve reliability and reduce ignition maintenance…Finding a HEI ignition, once easy enough, is now probably getting very difficult…

Dang I would look at other parts first, parsimony, start with the easy cheap repairs before going to hard expensive ones. What is the problem? I have never replaced a distributor, give us the symptoms for a less expensive repair solution. dot period end.!!

Key point going from a points ignition to HEI. You need to by-pass the ballast resistor circuits. HEI requires a full 12V from the ignition switch all the time. A points system uses 12V at start-up, but drops voltage to the coil to 6V through the ballast resistor once running.

Wasn’t the '73 model HEI?

Optional equipment from 1971 to 1974. Became standard equipment in 1975. OP didn’t state whether points or HEI. I was just covering the bases.

I still haven’t heard a specific problem. Before you replace a distributor you might use a timing light to check the timing and see if the timing advances as it should when you blip the throttle. Distributors can go bad, but it isn’t all that common.

You can upgrade the whole distributor, or if there are old fashioned “points” still in the current distributor a breakerless set up is easy to install and will provide plenty of spark using the current distributor, coil, and ballast. is a site that gives lots of ignition options from high performance systems to simple breakerless conversions of existing distributors that maintain the “stock” look of the motor. Before you spend a bundle of money (easy to do on high performance ignitions) you need to figure out exactly what problem you are attempting to resolve.

Even the old points systems when set properly (dwell, and timing) work fine. You just need to replace the points and reset them about every 20K miles.

If you want stock schmatics here are some:

Hope this helps.