1987 454 magnum tachometer not working

[isp184dude]

My tach has not worked for a while so I thought I would do some checking and see if I can get it working. There is a grey wire running along the back of the transom and when I hook it to the negative side of the coil the engine will not start but the tachouse needle bounces up and down while the engine is turning over. Am I missing something? Does that wire connect somewhere else? Thanks for your help. I appreciate it.

 

[Bondo]

Ayuh,.... Sounds like ya found the tach wire, 'n the gauge itself is probably junk,....

 

[alldodge]

The gray wire goes to the tach and to the negative side of the coil. What your seeing is why the wire is not connected, the tach is bad

 

[isp184dude]

I think the short is somewhere in the engine harness plug, rather than mess with that can I just run another wire from the tach to the negative side of the coil? It wouldn't be hard to do.

 

[alldodge]

I think the short is somewhere in the engine harness plug, rather than mess with that can I just run another wire from the tach to the negative side of the coil? It wouldn't be hard to do.

You can do that, but note the gray wire goes through the engine harness connector. Not using the connector is OK, just FYI

 

[isp184dude]

Thanks. I appreciate the help.