Trim tabs w/o switch or wiring

[AGENT 37]

I've got a set of used Lemco electric trim tabs (actuators and stainless 12x12 tabs) that I want to install. they were sent to me with the wiring cut off about 6 inches from the motor. Who has a suggestion of a good way to wire them? I was thinking about trying a couple of standard 3 position switches rather than an actual trim tab switch unit. I have no desire for indicators or auto retract and would like to do something different and save a couple of bucks. Or would the Lemco switch be better? I understand that they work by polarity (reverse the leads on the battery terminals and they reverse direction) but can't think of a real good way to go with my own control system for wiring them. As far as parts go, all I need to do it is the switches, fuse and wiring right?

 

[AGENT 37]

Re: Trim tabs w/o switch or wiring

Can any body tell me how many wires go to the back of the Lenco trim tab switches? Are they made so that it is easy to figure out how to wire if you don't have the factory quick connect plug?

 

[Boatist]

Re: Trim tabs w/o switch or wiring

Know nothing about them Mine are bennett but this may help.

http://www.lencomarine.com/ownersmanual.html

 

[Boatin Bob]

Re: Trim tabs w/o switch or wiring

Go to the link that Boatist provided and select the manual for products manufactured prior to 2007, about halfway down through the manual you'll see a diagram on how to retrofit the Lenco tabs to Bennett switches, they are basically a couple of DPDT switches that are momentary on - off - momentary on.

 

[PondTunes]

Re: Trim tabs w/o switch or wiring

You can use one switch to do it all if you pick up a couple of inexpensive relays, they just need to be set up to reverse current depending on which way the switch is pressed.

NOTE: This diagram was drawn for someone else so please ignore the wire colors as yours may be totally different.

The terminals of each relay will be connected as shown above to create a current reversing circuit..

1) Terminal #87 on each relay connected to fused +12v.
2) Terminal #87a on each relay connected to Ground
3) Terminal #30 on the left should be connected to the suspected UP wire of the trim tabs, while #30 on the right relay should be connected to the DOWN wire.
4) Terminals #85 & #86 on the relay energize the coil inside the relay One side should be connected to the same fused +12v as #87 was and the other should be connected to A Momentary SPDT Switch (A switch that is off in the center position and spring loaded so that it only engages while you press it)
The center position of the switch should be connected to ground.


How does this work??
1) When the switch is in the center position the relays are considered "at rest" meaning their coil's are not energized and internally terminal #87a & #30 are connected, thus both wires of the trim motor are grounded.
2) Lets say we press Up on the switch... The grey wire connected to terminal #86 on the left relay becomes grounded, since #85 always has +12v on it the coil in the relay energizes and closes the connection between terminals #87 & #30.. (The connection between #30 and #87a is no longer connected!!!)
This sends +12v down the purple wire connected to #30 on the left relay and a ground down the green wire connected to #30 on the right relay (since it is still at rest), resulting in the trim tabs going up..
3) If we press down on the switch the left relay stays at rest and the situation is reversed sending +12v to the green wire and ground to the purple.

 

[Boatin Bob]

Re: Trim tabs w/o switch or wiring

Pondtunes...I don't see how a single switch is going to raise and lower 2 trim tabs independantly??? Your circuit is fine for one but what about the other side?

 

[PondTunes]

Re: Trim tabs w/o switch or wiring

Bob you're right it won't run two switches independent of another, this would run both trim tabs the same if wired to both. if independent operation is desired another setup exactly like this would be required for the other side. A toggle could be used to switch between the two tab relay banks if desired or one SPDT for each side.

 

[Boatin Bob]

Re: Trim tabs w/o switch or wiring

That's what I thought but why go to all that trouble with the relays when a pair of DPDT switches will do just fine as per the diagram I mentioned above in the Lenco manual. Seems like the simplest way to achieve what he's looking to do.

 

[PondTunes]

Re: Trim tabs w/o switch or wiring

well other than having to run six heavy guage wires per switch from the trim motor's to the helm there isn't much difference.. Hooking up two sets using my setup would only require a short run to the battery and the wires to the switches would be grounds rather than having 6 wires with +12v and 6 grounds run all the way to the helm to get pinched, chaffed etc.

But either way will work.

 

[AGENT 37]

Re: Trim tabs w/o switch or wiring

The Lenco switch unit that I got a hold of had a stupid plug that would have been hard to make a good one that would hold up on my own. I went ahead and ordered a Bennett switch unit because it has brass screw terminal lugs on the back. I'll just wire it like Lenco says to do for the retrofit. Thanks for the help guys.