Hi guys. Newbie here looking for help with going through a mark 58a. I have the following wiring harness https://maxrules.com/oldmercs/Wiring/0_1965a/3.pdf. Was wondering if I can “Hotwire” it to check for spark and compression. I don’t have the control box or switch. Haven’t spent much time staring at the wiring diagram but was wondering which wires to connect to turn it over and get juice for spark. Or is there a simpler way I’m not thinking of? Probably is, I’m kinda slow sometimes. Thanks for any help
As long as the switch is not installed you can just power up the starter. Magneto ignition is self energizing, no external power needed. Be careful though, if it does start you have no way to turn it off.
Ok I was thinking that there was a kill switch to magneto that had to be dealt with. So what happens to that wire going to magneto when the ignition is off? It is grounded when key off, right? Is the automatic choke energized when in start but then circuit broken when key in run? Also I should ground plugs or wires when doing compression check, right? Thanks for your help, I’m a little rusty…..