Holley 4150 electric choke question - 1967 Mustang?

What's the proper way to wire up the electric choke on a Holley 4150 carburetor? I discovered one of the power wires for a modern radio had 30 ohms of resistance to grounding out, but measured 12 volts at the same power wire when the key was turned on. I have wondered if this is causing some of the problems the car has. The stereo is a Sony tape deck, which we installed brand new, but it's never sounded very good, even through good speakers. The power wire was yellow / black and connected to a plug that also had an blue wire attached to it, which was connected to another plug that had a power wire for the reverse light switch on the transmission. That same reverse light power wire had been tapped as the source for the electric choke on the carburetor, which grounds out through a resistor, which is not original, and I think it was causing problems with current flow to the radio. I could install a diode on either or both of the radio's power wires. I don't think that putting a diode on the power wire for the electric choke would make a difference. Does anyone have any experience with this or know something I'm not aware of?