Replace Johnson power trim relays with solenoid?

[jmadisonbiii]

I have a Johnson V-4 85, approx 1980. I have had problems with the wiring, relays etc. in the power trim box which attaches under the splashwell. Everything is older, corroded, dry-rotted etc. Is there any reason why I couldn't replace all of this with a solenoid like those used to operate ATV winches? The trim motor is fairly new and operates perfectly when straight-wired to the battery. Reverse the polarity and the trim motor runs the other way. Just like an electric winch.

 

[F_R]

Re: Replace Johnson power trim relays with solenoid?

Not familiar with ATV winches, but a "relay" is another word for a "solenoid". Or is it the other way around? Both are heavy duty high amperage switches, operated by a low amperage electro-magnetic coil. Sure, there are different configurations and shapes, etc. But I believe you are thinking straight.

 

[mikesea]

Re: Replace Johnson power trim relays with solenoid?

I cant recall if you have a 3 or 2 wire motor.That said,what I have successfully done is.Get a Ford starter solonid.Run your blue ,(up) wire to one of the large legs,bring a #6 maybe 8 wire from positive source to the other large leg,from your switch bring the UP to the small lug on the soloniod that activates the solonoid,bring the downside and attach it directly to the grn (down)motor wire.The reason for the soloind on the up ,is ,it takes a good bit more current for the upside due to weight friction etc,for motor to run without any lack of amperage,You can do the same for the downside ,but as long as your tilt tube that allows your engine to tilt has no heavy resistance,the wire to wire should work fine,Ive done it many times,if your engine is stuck,you might want to go for the 2 solonoids,they arent expensive aftermarket ,find a spot in the cowling to mount them,maybe on the rear exhust plate between the heads ,use one of the existing bolts for exhust cover,I only used one bolt and never had a problem,that will give ground to the soloniod.You probably should put a fuse in the feed line supplying power to the solonoid(s),if you have 3 wire you have a seperate ground to the TNT motor

 

[ezeke]

Re: Replace Johnson power trim relays with solenoid?

The reason you need a solenoid for the up movement on the three wire motor is so that the unit can offset the force of the engine at speed when in the trim range. It has little to do with tilting the motor up and down at low engine speed or when the engine is off.

You can use a reversing solenoid or two single solenoids on a three wire motor.

 

[McGR]

Re: Replace Johnson power trim relays with solenoid?

Just make sure the switches driving the solenoid coils can handle the additional load. The current required to drive most 12V solenoids is around 1 to 2A whereas a typical ISO style relay current demand is around 100mA. So, you're talking a increase of magnitude of a factor of approximately 10 or more. Also, the inductive kicks from the larger coils will probably be hard on the switch contacts. A typical trim switch may not be up to the task of driving the larger load of the solenoid coils.

Relays are cheap and available. Why not just stay fairly consistent with the original design? Beefing up the circuit with solenoids may improve the performance of the power side of the t/t circuit at the expense of reliability of the control side.

 

[ezeke]

Re: Replace Johnson power trim relays with solenoid?

......
Relays are cheap and available. Why not just stay fairly consistent with the original design? Beefing up the circuit with solenoids may improve the performance of the power side of the t/t circuit at the expense of reliability of the control side.

That will depend on the motor and what is there for a system to drive it. As you can see from the parts catalogs, in 1980 the motors were three wire and the control unit had a solenoid and no relays. In 1981 and up, most of the units were changed to two wire motors and the control units were changed to relays.

 

[jmadisonbiii]

Re: Replace Johnson power trim relays with solenoid?

I have a two-wire motor and a relay assembly (2 relays in a box about 6x6x1.5in.) in place now. Maybe someone retrofit it at some time? If the only downside to this swap is extra wear and tear on the switch, why not replace it with a heavier 2-way switch also?