Checked pins 2 and 3 with engine running: idle 44 mVAC. Voltage actually dropped with throttle advance. High RPM gave me about 24 mVAC.
Reinstalled Tach Amp and checked voltage cluster two pin connector. Here read 13 .4 VDC from fuse box. Also signal wire from Amp read 275 mVAC and increased with throttle advance as it should.

Although not positive i am almost convinced it must be the Tach itself. Just don't like swapping components without being more certain.


Update: scrounged up a cluster schematic for Tach. BK/RD wire is hot from fuse box and the other wire GN/BK is signal wire from Tach Amp. The signal wire is a straight run from Tach Amp pin 3.

Funola, i misinterpreted your above post and read pin 3 voltage at amp connector. I went back today and read at the cluster as i should have the first time. If i understand the pickup correctly then having this mVAC at cluster signal wire along with increase with throttle tells me the pickup and circuit through amp is acting correctly.

Looks like the tach body serves as ground to the cluster body then through the large multi pin cluster connector. So i either have a ground issue or dead Tach. Does anyone know what the actual Tach resistance should be reading at the back of the cluster(two pins)? Mine is reading .76 meg ohm. I would think a functioning tach would read higher than this.

Comments appreciated.
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