Thanks for the manual Karl, it helped alot and it looks like I may just have a bad tach. I have a ground and 13 volts with the key and it appears I have signal from the motor, although I'm not sure, I read .6 volts when the motor is running but can't read milliamps.

So does anybody have a late model tach they want to get rid of cheap? I will be greatly indebted to someone if they do and I can get it by the 23. You can email me direct if you want at This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Thanks
Ron

When you say .6 volts... is it .6 DC volts that your testing? or .6 AC volts?

It should be AC voltage and change with engine speed.

But maybe I have misunderstood your post.

I saw .6 dc, should I see ac voltage? Also do you know how the gauge gets its signal from the motor, does it come straight from the coil or go through the DME. I was sure I had a wiring issue but I'm going to order a used tach from EASY tomorrow.

The signal should be measured with AC voltage. Test the signal wire on the AC volts setting on your DMM (digital multimeter) the voltage will change with engine speed. I have the factory workshop manuals but the wiring diagrams differ from year to year. Please specify what year the car is. I am assuming that it is a N/A 8-valve.

According to the wiring diagrams though the ignition coil receives its signal from the DME.

The car's an '86. Every wire that I took out is accounted for. The only things I wasn't sure about were the altitude sensor and 2 big resistors, both of which were under the dash. I wired them back up the way they were but it made no difference. The guys at EASY are sending me a tach to try and see if it works. If so, I'll buy it.

Ok so according to the wiring diagram and my understanding of it:

The DME gets its signal from either the reference mark sensor or the speed mark sensor. The DME then sends 2 signal wires:

1. to the ignition coil it is green.

2. Then one to the tach. it is sent through the 4 pin plug at the DME and it is in pin #2 and is Green/Black.

I would test the green/black wire on AC voltage.

Good Luck please tell us what you discover good,bad, or otherwise.