Adding Cowl Trim Switch

[R5B4]

I am wanting to add a trim switch to the cowl of a 1999 force by mercury 40 hp outboard. The part -87-850691/ It has a green wire, Blue wire, and red wire. Can I just unplug the wires and insert these to the nearest plug as shown in the first picture. On youtube someone stated you can’t use those but need to go to opposite side of engine and connect there, Of course the wire on plug is not long enough to go to other side. See switch picture. Then final question where do you plug in the red wire? Again only thing I can find on youtube is to splice it in on other side of engine. I really don’t want to splice it if I can get away without doing that.​

 

[DaleH]

Adding to the cowl by swapping in at those plugs means the remote control will no longer trim the motor.

You can lengthen those wire to that switch ... just use good technique, good marine butt connectors, AWG tinned wire, and adhesive-lined heatshrink over the connector and you'll be fine.

Red is any 'hot', and to complete the circuit at the connections by the Trim relays, blue = sky = UP, where green = grass = DOWN. See 'typical' schematic.

Strongly recommend you temporarily hoot it up and confirm the operation before you go cutting in the cowl switch.

 

[JL8Jeff]

I have a 94-95 Mercury 60/45 that I added the power trim/tilt to and it had the wires/switch to the cowl as well as the wiring to the console so let me check in the morning to see what connections I used. I know the kit I got from Merc was for the later stuff so the relays are not in the right spot, but it has been working for 5-6 years so far.

 

[R5B4]

Adding to the cowl by swapping in at those plugs means the remote control will no longer trim the motor.

You can lengthen those wire to that switch ... just use good technique, good marine butt connectors, AWG tinned wire, and adhesive-lined heatshrink over the connector and you'll be fine.

Red is any 'hot', and to complete the circuit at the connections by the Trim relays, blue = sky = UP, where green = grass = DOWN. See 'typical' schematic.

Strongly recommend you temporarily hoot it up and confirm the operation before you go cutting in the cowl switch.

View attachment 113764

On the red wire I need to splice it into another red wire on the motor? There is no spare butt connector already on the wiring harness? Only reason I ask is I put in a cowl switch on another motor I had can't remember if it was a Mercury or a Johnson and all the connectors where already on the wiring harness.

The wires in the second picture are solid green and solid blue. I guess after reviewing the trim wiring guide from service manual. Those wires are going from trim relays to the trim motor. So I would need to find the grn/white and blue/white wires.

Which remote switch would stop working- at the bow or switch on throttle handle?

Thanks

 

[JL8Jeff]

I looked at my motor today and I just have the blue/white wire and the green/white wire plugged in. My red wire is not connected to anything. But I have the cowl switch and the trim switch on the controls at the center console so it might be getting power from the main wire harness. My cowl switch is a little different but the wiring is basically the same. Do you have key start and normal controls for the motor? If so, you probably don't need to hook up the red wire. Which side of the engine is the cowl switch on?

 

[R5B4]

I looked at my motor today and I just have the blue/white wire and the green/white wire plugged in. My red wire is not connected to anything. But I have the cowl switch and the trim switch on the controls at the center console so it might be getting power from the main wire harness. My cowl switch is a little different but the wiring is basically the same. Do you have key start and normal controls for the motor? If so, you probably don't need to hook up the red wire. Which side of the engine is the cowl switch on?

Yes key start and normal controls with trim switch on throttle and at front of boat. The opening for the cowl switch is on the right side when looking from back of boat. I am suppose to get the switch on Monday, so I will try it without hooking up red wire first. Thanks

 

[thill]

I am wanting to add a trim switch to the cowl of a 1999 force by mercury 40 hp outboard. The part -87-850691/ It has a green wire, Blue wire, and red wire. Can I just unplug the wires and insert these to the nearest plug as shown in the first picture. On youtube someone stated you can’t use those but need to go to opposite side of engine and connect there, Of course the wire on plug is not long enough to go to other side. See switch picture. Then final question where do you plug in the red wire? Again only thing I can find on youtube is to splice it in on other side of engine. I really don’t want to splice it if I can get away without doing that.​

The short answer is YES, you can connect to the existing Red/Green/Blue wires THAT GO TO THE EXISTING SWITCH. This can be done inline since the switch you show in Pic 1 already has the jumpers to be added inline with other switches.

DO NOT connect to the wires in Pic 2 that go to the trim motor! Those are NOT the right wires, and will cause you instant problems. The blue and green wires you want to connect to can be seen near the main plug at the bottom center of Pic 3.

After connecting the blue and green you see in that pic, you need to connect the red wire to the fused circuit currently being used by the other trim switch, the one with a 20A fuse.

As stated by others, I recommend against cutting anything if you can possibly connect to existing connectors. Make up some jumpers, and make sure they are of the proper gauge, probably 14 gauge.

I hope it works out for you.

 

[wmk0002]

All good advice thus far. I'll only add that I would splice the red 12V power wire on the switch to a non keyed power supply so you can trim the motor without having to turn the key. That's how most all standard cowl switches work plus the switch on the remote.

 

[R5B4]

Thanks for all the advice. I finished the installation of the trim switch. So what I did is trace the wires from the relay which was the green/white and blue/white wires. Near the front right side near the starter I found these wires had bullet connectors similar to the switch I previously shown. So I took the switch and the blue and green wires I cut mid way and insert a length of 20 gauge wire same as original switch so then the male and female bullet connectors reached the connectors by the starter. I also extended the red wire to reach the other side of motor. Then I made a red wire with 2 female connectors going into a single wire with a male bullet connector. I then traced a power line from the fuse on right side of engine found where it had a male female bullet connector pulled them apart and inserted my y-connector into the original wire and then connected both the original red wire and the red wire from the switch. I have included pictures of the connectors by starter, the extend wiring with switch, pro-type of y-connector, y connector installed. Again thanks to all that responded with your help.

 

[DaleH]

Sweet!

 

[LDUBS]

Looks like it came from the factory that way!

 

[thill]

Yes, you did it the right way. Excellent!

 

[JL8Jeff]

Looks good, I wonder if you really needed to connect the red wire or not. I know both my trim switches work without the key in and I didn't connect the red to the cowl switch. You may want to disconnect the red wire and see if both switches still work.

 

[LDUBS]

Looks good, I wonder if you really needed to connect the red wire or not. I know both my trim switches work without the key in and I didn't connect the red to the cowl switch. You may want to disconnect the red wire and see if both switches still work.

Now that you mention it, mine is the same. Both switches (motor and remote) work without the key in.