I bought an aftermarket o2 sensor and air fuel gauge. I wired the switched and constant wires to the radio. Well turns out when the radio is loud the air fuel gauge bounces with the beat. So...I assume its the constant 12v wire.I should change? Is there another constant 12v that's easy to access under the dash or somewhere else close by? Also not sure if I'm in the right section or not for this, but what should I be at at idle, cruising, and WOT? I have a carbureted 355 in it.

 

Have power seats? Tap into the line for that. There are other lines under the dash that are constant, usually big orange or red maybe pink wires. Just need to probe for them

 

Do you think its the constant twelve that the radio is drawing? Or the switched? Idk enough about radios. Its aftermarket.

 

No idea what wire you used so i cant comment. No idea why any power feed to radio would pulse a wideband

 

Idle and crusing, a carb should run around 14.7. At acceleration, the AFR should drop into 13's but with a carb, who knows where it will take you.
At cruising, a good EFI system will lean out the mixture to 16's (sometimes even up to 18's) to save fuel. But carbs are not equipped to do that. Unless you have a CCC system.

 

You might try the cigarette lighter socket for the 12v source.

 

There's an open BAT terminal on the fuse box, get the proper connector @ vatozone or wherever and plug it in. The connectors for BAT and IGN are different, they do not interchange (for a reason)

 

I thought I was the only one who called it that

 

Well I rewired it to a different constant 12v source and still the same. So the next thing I'm going to try is using a jumper wire all the way to the battery and if it still does it, I'm going to change the switched 12v.