1987 Ford Mustang 2.3L 4 cyl. suddenly did not start about 2 weeks ago. Installed a new starter relay. Car started & ran fine for 2 weeks. Today, no start, no indicator lights, just a “click”. While using jumper cables, I noticed that when I had no indicator lights, the Tach needle was slowly climbing until it reached 500 RPM-AND THE ENGINE ISN’T RUNNING!!!. The Hayne*s Manual is as clear as mud as to where the Tach gets it’s input. Does it work like tach’s of yesteryear off the distributor? Or does it get it from another sensor in the engine and could either of these be where the short is?
The problem isn’t being caused by a short, there is a bad connection somewhere. If you haven’t removed the battery cable connections and cleaned them along with the battery posts I suggest you do that first. It is amazing how many problems like this is caused by bad battery connections. If that doesn’t help then check the power getting to the fuse panel under the hood while you try to start the engine and see if 12 volts is getting to that point. If it isn’t then there is a problem with the wire to the fuse panel. I think there is a fusible link in the that wire.