Power Trim - Solenoids to Relays

[Raghauler]

RE: 1987 115 HP I6 ELPTO

My power trim unit is shot, so I received a replacement that will fit - with no wiring diagrams - and is wired very differently than the old original:

(UPPERCASE = LARGE POWER WIRES, lowercase = small signal wires)

Old wiring: red-white, blue-white, green-white wires from trim switches to up/down solenoids, with BLACK GROUND and BLUE & GREEN POWER WIRES from the solenoids to the trim motor. Red-white wire from the harness (switches) has a fuse that then connects to the solenoids with RED BATTERY POWER (from starter solenoid) connected through both solenoids on the opposite end (What is the purpose of this?)

New wiring: RED FUSED POWER WIRE to blue wired relay, and BLACK GROUND WIRE to green wired relay, with each relay having small (signal) wire (with white stripes) and LARGE (POWER) WIRE to be connected to the trim motor, along with multiple black (small) wires connecting between the relays.

I assume I remove the solenoids and install the relays with the RED FUSED POWER WIRE connected to the starter solenoid (battery), and connect the thin blue-white and green-white signal wires directly to the trim switch wires of the same color, connect the respective BLUE and GREEN WIRES to the trim motor, and connect BLACK WIRE to ground in the motor. If so, what do I do with the fused red-white wire coming from the trim switches?

Or, could I just keep the solenoids, and connect the respective BLUE and GREEN wires between them and the trim motor?

I need a quick fix as I?m water-bound with our without power trim next week. I prefer with.

 

[Raghauler]

Re: Power Trim - Solenoids to Relays

OK, after bench testing, I figured out everything except the red-white fused wire coming from (or too?) the trim switches. Can anyone tell me what to do with this?

Here's a wiring diagram attached.

 

[gregpro50]

Re: Power Trim - Solenoids to Relays

That red wire gives constant power to the solenoids. That is what powers the trim motor when you push the trim button up or down. The solenoids click when it gets a trigger signal from the controls and closes the circuit to power the trim motor. Its just like a starter solenoid in a car.

 

[Raghauler]

Re: Power Trim - Solenoids to Relays

Gregpro, thanks for the response... that's not the wire I am questioning. The power to the trim solenoids comes from the battery lead at the starter solenoid, which is hot at all times. The wire I am trying to figure out is the RED one coming from the powered terminals at the trim solenoids that goes to a 20A fuse, where a smaller ga. red-white wire goes back to the trim switches. I figured that this provides 12V at the trim switches, but when I disconnect it, the switches still work. That's not to say the trim switches weren't jury-rigged by a previous owner as I have two connections at the battery: the normal large power cable, and a smaller wire that, when disconnected, the trim switches do NOT work. That may be my answer, but I was wondering if anyone could tell me what the wire in question is SUPPOSED to do. And should I connect it to the starter solenoid battery connectionwhen I replace the solenoids with relays, as that's what it does electrically right now?

Thanks again.

 

[j_martin]

Re: Power Trim - Solenoids to Relays

That's the power supply to the trim switches. Many boats get power for other trim switches from some other source, sometimes switched by the master power switch.

It's easy to see how things get mixed up. Any 12 volt supply point should work. Just be sure it's fused so a shorted solenoid will cost you a little frustration instead of burning down your bote.

hope it helps
John