Trim Sending Unit Purpose.....???

roozterdvx

Seaman
Joined
May 29, 2006
Messages
57
Going through this past weekend cleaning and doing maint. on the boat and I noticed the trim sending unit broken, (mounted on the top pin of the hydraulic ram). It's just barely hanging on there.
I don't have a trim gauge, so can I remove the sender without any problems or does it serve some other purpose such as possibly high and low travel limits?

The motor is a 1998 Mariner 225 EFI.

Thanx in advance.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,778
Re: Trim Sending Unit Purpose.....???

I would assume so. The sending unit is probably just a variable resistor which is wired in series with the trim gauge (if you had one). Current thru the gauge is controlled by the resistor wiper's position.

I would assume that the connections to it (wiring harness side) are structured such that no terminals are exposed which could come in contact with metal and short out your 12V power. If so, cover them up with something....heat shrink tubing, electrical tape......

Mark
 

roozterdvx

Seaman
Joined
May 29, 2006
Messages
57
Re: Trim Sending Unit Purpose.....???

I would assume so. The sending unit is probably just a variable resistor which is wired in series with the trim gauge (if you had one). Current thru the gauge is controlled by the resistor wiper's position.

I would assume that the connections to it (wiring harness side) are structured such that no terminals are exposed which could come in contact with metal and short out your 12V power. If so, cover them up with something....heat shrink tubing, electrical tape......

Mark


The housing is broken and separated in two. I can see the "wiper" and what appears to be a spring. Can I remove it completely and disconnect the wiring? Will it affect high and low limit travel. I don't trim the engine up fully because it starts bending the control cables in the splash-well, and I know by the sound of the trim hydraulics that the engine is down all the way. If the sensor is fuctional, (read: not broken), will the hydraulic trim motor stop when the motor is completely down on it's own. What I mean is, is the sensor only for a trim indicator gauge?

Victor
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Trim Sending Unit Purpose.....???

The housing is broken and separated in two. I can see the "wiper" and what appears to be a spring. Can I remove it completely and disconnect the wiring? Will it affect high and low limit travel. I don't trim the engine up fully because it starts bending the control cables in the splash-well, and I know by the sound of the trim hydraulics that the engine is down all the way. If the sensor is fuctional, (read: not broken), will the hydraulic trim motor stop when the motor is completely down on it's own. What I mean is, is the sensor only for a trim indicator gauge?

Victor

The sensor is only for the trim indicator gauge. The single wire goes up into the cowl, and connects to a plug wired into the harness plug. Even if it got shorted to ground, no harm would be done, as the power is supplied, and that very limited, from the gauge. (the one that's not there) You can chit can it without any problem.

hope it helps
John
 

roozterdvx

Seaman
Joined
May 29, 2006
Messages
57
Re: Trim Sending Unit Purpose.....???

Good to know.
I'm taking it off and pulling the wiring back to the connector.
Thanx.
 
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