1970 Mercury 500 switchbox installation

[ryerman]

The previous owner had removed the switchbox, sent it in as a core and got a "new" switchbox. He said spark was intermittent. Good spark at first crank, then nothing. He never installed the switchbox, but wire leads are all labeled. Any harm in installing the new switchbox and firing this motor up?

 

[chum1]

Re: 1970 Mercury 500 switchbox installation

I would get a wiring diagram and study the schematic before hooking it up, some of these switchboxes can't take the mistake of crossed or shorted wires and could burn out quick, the trigger assy. may also be suspect on no sparkage.
cdi has a good troubleshooting guide http://www.maxrules.com/CDITSHOOTING.html,
As with any of these engines you must usually correct 40 years of hay wiring, troubleshoot, then replace components as necessary.

 

[ryerman]

Re: 1970 Mercury 500 switchbox installation

Thanks so much. I'll check the diagrams and study up before attempting any further installation.