1984 Johnson 235hp wiring question , to dash switch !

Heywire77

Petty Officer 2nd Class
Joined
Jun 19, 2012
Messages
101
I have a Johnson 235hp and my boat is a 1997 Ranger 518svs and it had a Mercury 200hp outboard before it blew up , the questions is my ignition switch is on the dash and the used Johnson motor has it in the control can I switch it to the dash switch instead ? Also is there anyway to use my control from my Mercury motor because it is a newer flush mount control and much nicer ? All that would be going to it would be the cables and the kill switch wiring ?
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
The control cable from the Merc box won't adapt to the red plug under the Johnson's cowling. You'll get into problems if you try to rewire that connection without a factory wiring diagram for both engines. The two key switches are similar in operation. The Johnson switch likely has connectors on the back. The merc switch (if that's what Ranger used) usually has a wire pigtail coming out the back-no connectors. They function the same, but again, you will be into cutting, splicing and crimping wires, referring to both wiring diagrams. Generally this is not the best approach long term in either case. These makeshift connections may fail at some point in the future since they are not as robust as the factory connectors. You could wind up with an electrical malfunction. You'll have to compare the action on shift cables. the engine ends may be different. Also, make sure the control cables move the same directions when shifting/throttling. Think I'd be looking for a used OMC conceal side mount control box with wire harness instead.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Yep, get the correct parts. You can always flip the Merc bits on eBay or Craigslist.
 

Heywire77

Petty Officer 2nd Class
Joined
Jun 19, 2012
Messages
101
It was actually so easy to do it ! The wiring is exactly the same colors for each item so I just didn't use the big plug and made connectors for each wire and heat shrieked them so shouldn't be a problem I save the big plugs in case I ever change motors and have to hook it back up . And the shift and throttle cable was easy also I took the cables out the old crappy looking omc control box and put them in my commander 3000 control box on the other side instead of the side they had the Mercury cables hooked there is another side in the box . I found out that all boat wiring uses the same color code after 1979 for all wires so if it is hooking to a tach then the wire color would be the same on a Mercury as a omc !
 
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