DIY knock sensor light

Has anyone made an indicator light that shows when the knock sensor is pulling timing out of the EEC? I pretty determined to do it but if someone else has already figured it out I'd rather follow their lead than reinvent the wheel.

I have found that MSD makes one but it would replace the current knock sensor so you would no longer have the protection of the factory one. That's not as much of a deal killer as the $180 price.

I read through the thread from a couple of years ago on this where Rob North was going to make one and then didn't. There's a few good leads on that thread that I'll follow.

Sounds like a good idea. I'm not sure what the "pinging" sound everyone talks about even sounds like. I can understand an LED.

Are you an EE by any chance, Sly?

Do you know what type of signal the knock sensor produces?

I am not an EE.

The sensor sends a sound signal (AC) current. The EEC interprets it to decide whether it's noise or knock.

I did a little reading on this in old forum posts, and it appears to be a tricky proposition. The knock sensor produces momentary spikes of AC voltage when the crystals inside it resonate. They only resonate at a certain frequency which is chosen to correspond to the engine that the sensor is mounted on. (So knock sensors from a 4.6, for example, will probably not work on a 3.8.) The trick with making a knock light is that the voltage spikes are so high and so fast that it's probably not even able to light an LED reliably. Or it would, but the flashes would be so short that you wouldn't even notice. Also, there is a certain amount of background noise present, as noted in the linked thread.

So in other words, this would be fun!

I'll put this on my mile-long to-do/think about/research list (for the SC...I've got other lists like this too )

Yeah, how come my "Supercoupe To-Do List" only gets longer as time goes by? Something is out of kilter.