tach signal?

[jakeb]

I have a m42 swapped into a 2002 and trying to get the tach to work.

Does anyone know what type of output the e30 m42 tach pin on the c101 gives out? It is pin 9 btw.

I know what the 02 tach needs just need to know what the m42 signal is so I can make something to convert from one to another.

thanks...

also if anyone knows the resistor range for the gauge temp sensor.

jake

[PiercedE30]

I believe it's just a 5v square wave output. Don't quote me on that, but I'm pretty sure that's what it is.

[jakeb]

I think you are right. Is there a way to test that with a MM.

I wonder if something like this would make my stock tach work.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=MSD%2D8920&N=700+115&autoview=sku

[jlevie]

I think you'd need to look at the tach signal with an oscilloscope to see what the waveform and level is. A 5 volt square wave does sound right.