Connecting 3 wire to 2 wire relay

Chiselbill

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Jan 15, 2019
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Changing outboards vro 1990 90hp, just realised the one I’m putting on has 3 wire tilt trim old one 2 wire, I’m trying to figure the easiest way to connect it can someone help me out please?
 

Scott Danforth

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welcome aboard

relays have 4 or 5 terminals 2 for the coil and at least two for what you are switching.

if your new relay has 2 coil wires and 3 main connector relays, one will be common, one will be normally open, one will be normally closed. wire your battery connection to the common terminal and the normally open to the trim wire. the normally closed terminal would not be used.
 

Chiselbill

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Ok thanks! But can I take the middle wire out of the relays and connect the black spare trim motor wire to Common
 

racerone

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Yes , many times a seller will say.----" they are all the same "-----Or the other one ----" you can make it fit easy " ---------So you need to get the solenoid for the 3 wire system.----Possibly a different switch for the throttle handle.----The 3 wire uses the solenoid for up and the handle switch for down.----Possibly more current through the switch for the down function.
 

Chris1956

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3 wire trim motors have power supplied to either one of the colored motor leads, while the common black wire is always grounded. That is, power is supplied to one of the colored (green or blue) wires, and the other colored wire is left UNCONNECTED (not grounded).

2 wire PTT motors always have either power or ground on them when the trim is operating. power on blue makes her spin in the up direction.

Therefore I believe some relays can be used for a 3 wire trim motor. If the relay has 2 ground wires on it, one to complete the circuit to energize the relay and the other to supply ground to the motor, when the relay is not energized, you should be able to disconnect the ground to the motor on both relays and it should work with a 3 wire motor. Remember to ground the black wire..
 

Joe Reeves

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Using the relay setup = Change the 3 wire PTT motor to a 2 wire motor

Using the 3 wire PTT motor = Do away with the relay setup & install the PTT solenoid setup/

Whichever is easier!
 

Chiselbill

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Thanks for the help.i just went back to the solenoid 3 wire setup but tilt trim is struggling on the bigger single ram, I'm starting to get a bit annoyed any advise thank you.
 

Joe Reeves

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Thanks for the help.i just went back to the solenoid 3 wire setup but tilt trim is struggling on the bigger single ram, I'm starting to get a bit annoyed any advise thank you.

You'll need to go into detail as to what you mean by that. I'm only guessing that it vibrates or is slow going up.

To test the electric motor if that's giving you a problem... disconnect the three wires of the motor at its connector.

With a known good fully charged battery & good jumper cables of the proper size, connect the negative jumper to the motor's black wire.... then, connect the positive jumper to one of the other motor wires... green then blue to test the Up & Down mode.

If the engine tilts okay in both modes, then obviously the electric motor is okay... BUT if not... then you have a bad wiring connection somewhere, improper wiring, assuming the battery & jumpers are okay.
 

flyingscott

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Can you just swap the tilt and trim between the motors. anything 78 to about 92 will interchange.
 

Chiselbill

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Jan 15, 2019
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All good scored a 115 for a cartoon put that on and it runs great, I can mess around Witherspoon the 2 stairs now.any one know much about adding another battery and how much more juice a 115 will drink than a 90?
 

sam am I

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3 wire trim motors have power supplied to either one of the colored motor leads, while the common black wire is always grounded. That is, power is supplied to one of the colored (green or blue) wires, and the other colored wire is left UNCONNECTED (not grounded).

2 wire PTT motors always have either power or ground on them when the trim is operating. power on blue makes her spin in the up direction.

Therefore I believe some relays can be used for a 3 wire trim motor. If the relay has 2 ground wires on it, one to complete the circuit to energize the relay and the other to supply ground to the motor, when the relay is not energized, you should be able to disconnect the ground to the motor on both relays and it should work with a 3 wire motor. Remember to ground the black wire..

I agree.........The old system (2 wire relay) running a 3 wire PTT will work.

With the 3 wire PTT's, the motor's coil is center tapped to ground(blk), the 12V is switched on to one side (grn for example) while the other side (wht for example) floats (no current flow).......This is done with solenoids of course.

If a guy hooks up the relay's setup 2 wires, grn and wht to this 3 wire PPT motor's grn and wht leads directly and respectfully, the only thing that'll happen is instead of floating the non-energized side (wht in the above example) is wht will just be grounded instead of floating.

Since the motor coil's is center tapped to ground as stated above, there is still no current flow still between ground and wht due to the fact wht is also grounded.The reverse holds true as well when the PPT's motor switched to the opposite direction.

My only concern would be, as Race mentioned, the current!! Can the relay's handle the 3 wire PPT motors current? Is it a higher draw motor? Higher then the relay's spec'd current?If not, all is well IMO.
 
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