I am in the process of trying to get my tach working. I baught a used one under the assumption that mine had an internal issue. The second used one I picked up also is not working when I hooked it all up.
I read on an old pelican forum that you can test the tach by connecting it outside of the wiering harness by connecting the + to Power the - to ground and the blk/purple plug directly to the - on the coil. Would this infact work? What if you dont have the original coil, but a replacement one? would that matter?
I connected the + of the tach to the + on the batt, then the - of the tach to the - on the batt. I then connected the blk/purple connector directly to the - on the coil. Am I doing somethint wrong here?
Are these VDO Tach known for going out? Any help would be great! This is all on a 1970 914 4 1.7