Mercontrol Rewiring

[Chuck93]

Opened up this mercontrol on my 1970s StarCraft holiday with a 1150 to address the choke button not working and found another can of worms is it possible to find the parts to rewire this or is it possible to retrofit a new control to these cables and wiring harness

 

[Scott Danforth]

Both..... Depends on what you want to do

 

[alldodge]

Very few parts available for it
https://www.mercruiserparts.com/bam/subassembly/32081/2128/140

 

[Chuck93]

I would be leaning towards a new control retrofit there's really nothing left to splice the wires to and all the switches/ wiring harnesses seem to be unavailable. Is there a specific mercury control that is easer to retrofit?

 

[Chris1956]

You can likely get a new keyswitch and choke button. Perhaps a new neutral safety switch. I had a control like that one, and needed to rewire it one day. Hopefully the mechanical bits are still good.

The issue is that the quick disconnect boat harnesses go bad, and I do not know of a replacement for those. Also, the engine wiring harnesses also go bad by this point.

 

[Scott Danforth]

not much money to rewire it. switches available if you look.

 

[Chuck93]

I’m trying to wire in a temporary key switch and choke picked up a switch at a boat shop that they said could be made to work but there’s a couple things that I’m not understanding where does the orange wire from the original harness tie in and what would go to the magneto wire on the new switch

 

[Chris1956]

On those MerControls, Mercury wired them so they will work with battery-powered CDI ignition, as well as ADI ignition. That is, they have an ignition power supply and an ign killer wire going to the motor. The motor uses one or the other.

On an 1150, 1979 1/2 was the changeover from battery-powered CDi ignition to ADI. so which year 1150 do you have?

 

[Chuck93]

The serial number is 2838067 which would say it’s a 1970 I know it’s one of the earliest models of 1150 because it has a silver block

 

[Chris1956]

OK, so it would appear that you need an ign switch that has an "I" terminal for ign power. Is that what you bought?

 

[Chuck93]

On the diagram for the switch I bought it shows the purple wire as going to ignition but I really don’t know this new switch has six terminals and the old has seven so missing something somewhere

 

[Chris1956]

Purple is the new wiring color for ign power, replacing your white wire. It also needs to feed the choke button, to power it.

Other terminals on the switch that you need are battery, solenoid (feeds neutral interlock switch in series), you will likely have a ground on the switch as well.

 

[Chuck93]

So what about the black with yellow stripe wire labeled magneto on the new switch is it not needed with this type of ignition?

 

[Chuck93]

I wired it up
Black-black
Red-Red
Yellow-Yellow with red stripe
Grey-Yellow with black stripe
White-purple
Salmon-Black with yellow stripe

Everything seems to work was able to start the motor for the first time

 

[Chris1956]

The wire colors appear to be correct. Good luck with it.