Help with a wiring project

February 1, 2011 | By Richard Prince

Question:

I have a question regarding wiring a 1964 Falcon Ranchero. I changed the dash and have run into a couple of things I wasn’t prepared for. The big one is the resistor wire between the ignition to coil and starter relay. I have changed the distributor from points to electronic so I’m wondering is that resistor wire there to reduce the voltage from 12 volts to 8 volts so the points don’t weld together? If that’s the case then do I need to have it connected to the coil?

The other question is regarding the new gauges I’ve installed in the dash. I took out that ugly cluster and built a new dash face and went to six individual gauges. Everything has been wired up according to the old gauges, and it all works. The voltage gauge isn’t wired yet because the new gauge has two posts, one for the light and one for power, but there are two wires, one from each side of the old gauge. When I power them up they are both hot, and when there’s no power they both go off. Can I just connect them together and run the one wire to the power side of my voltage gauge?

Answer:

Whether or not you should incorporate a resistor in the ignition system depends upon the recommendation that the manufacturer of your electronic system provides. The answer varies depending on exactly which system you’ve installed. Consult the instructions that came with your system and if that doesn’t yield an answer contact the manufacturer.

In general, my answer to your gauge question is the same—follow the manufacturer’s instructions. You refer to your new gauge as a “voltage gauge” and if it is, in fact, a voltmeter the simplest way to wire it is to connect the appropriate post to a power source that’s hot only when the ignition switch is in the run position and connect the other post to a good ground. An ammeter should be installed in series between the positive battery post and alternator charging terminal.