tachometer signal

[blk94xlt]

I am trying to figure out what the tachometer signal should look like on a 96 explorer 5.0.
I'm measuring the signal at the datalink connector under the hood, and on a scope I read a square wave of about 0.8Vp @ 63Hz with a 50% duty cycle when the engine is at idle. As I reved it up a little the frequency of the signal increased and the amplitude stayed the same, so it looks like its reacting correctly.

I was expecting to see a higher amplitude than that but have never heard of the actual voltage measurement that should be there on the T/Y wire going to the gauge.

My tach gauge is not working and I'm starting the troubleshooting process. I'd really like to know what the signal is supposed to look like at idle.

Thanks

 

[rego]

Pound the top of the dash and the tach may work for a short while. Mine does. That may somewhat isolate the problem area. I am not an auto tech.

 

[blk94xlt]

yeah..... that's how I used to get my old Toyota camry instrument panel to light up when it decided it didn't want to.

This time I'm going for a different approach. But I'll keep that in mind as a last resort.