Possible to adapt 4-wire (MerCruiser) Commander 4000 switch to 3-wire (Outboard) trim

[jim_s]

I have purchased a used Commander 4000 shift/throttle unit to replace my malfunctioning 3000 unit. The 3000 unit's trim switch has 3 wires. The 4000 trim switch appears (based on component diagram in document 90-814705R03) to have come from a MerCruiser setup, and has a red wire that my 3000 unit does not have. Can this red wire simply be ignored? Is there something else that I can do to adapt the 4000 unit's 4-wire trim switch to the outboard 3-wire setup? Worst-case, will the old 3-wire switch from my 3000 unit fit into the 4000 handle?

Any assistance is much appreciated!

 

[jim_s]

Re: Possible to adapt 4-wire (MerCruiser) Commander 4000 switch to 3-wire (Outboard)

BTW, for some added clarity, the wiring on the trim switches for the two units are:

existing 3-wire switch:
- Blue/White
- Green/White
- Red/Purple

new 4-wire switch:
- Blue
- Green
- Red
- Purple

On some further looking in the Capri Owner's Manual, there is a diagram for the outboard and stern drive models, but the diagrams don't exactly gybe with what the actual wire colors are.

The diagram for the outboard shows a Red/White wire as apparently the power coming into the switch, then a Green/White as 'Trim/Trailer Down', and a Blue/White as 'Trim/Trailer Up'. (I've got Red/Purple, Green/White and Blue/White on my 3-wire switch - I'm assuming my Red/Purple is the Red/White in that diagram.)

The diagram for the stern drive shows a Red/Purple as 'Trim Power', then Green/White as 'Trim/Trailer Down', Purple/White as 'Trim Up', and 'Blue/White' as 'Trailer Up'. These wire colors don't correspond to the wires on the 4-wire trim switch.

So, it seems a decent bet that Green on the 4-wire switch is likely equivalent to Green/White 'Trim/Trailer Down' on the 3-wire switch, and Blue on the 4-wire switch is likely equivalent to Blue/White 'Trim/Trailer Up' on the 3-wire switch - I just have no idea if red on the 4-wire switch is the 'power' or purple on the 4-wire switch is 'power', or if my guesses on any/all of the above are all wrong. (I'm disinclined to just start hooking stuff up willy-nilly as an experiment, as I have no idea of what the consequences would be of screwing something up, but it sounds potentially expensive.

 

[jim_s]

Re: Possible to adapt 4-wire (MerCruiser) Commander 4000 switch to 3-wire (Outboard)

Ok, with the arrival of daylight, I did a little exploring of the new switch with my DVM. It seems that Red is power, Green is Down and Purple is Up. I couldn't find a path between Blue and any of the other 3 wires, no matter what I did with the switch, so I have no idea why Blue is there. For my purposes, however, I just need Power, Up and Down, so I think I'm in good shape at this point!