1972 120 mercruiser trim guage pegged down

[Lewis72]

Hey all, i fixed my idle issue i posted about a wile ago but im also having a problem with my trim guage. My trim works fine but the gauge will not buge from the down position. All my other gauges work exept this one i just dont understand why. It has no sender units on the bell housing but im pretty sure its in the boat towards the left. Could any one point me in the right direction on how to fix this?
Thanks!!!

 

[alldodge]

Re: 1972 120 mercruiser trim guage pegged down

Hey all, i fixed my idle issue i posted about a wile ago but im also having a problem with my trim guage. My trim works fine but the gauge will not buge from the down position. All my other gauges work exept this one i just dont understand why. It has no sender units on the bell housing but im pretty sure its in the boat towards the left. Could any one point me in the right direction on how to fix this?
Thanks!!!

The trim limit should be on the port side and the trim gauge sender should be on the starboard side of the gimbal ring. If you have neither then your gauge will not work and you could over trim while running which could in turn damage your drive u-joints. Are you sure you have neither?

If the wiring is there, the Brown/White wire comes from the trim sender to the gauge. The sender has two black wires coming from it, one goes to ground and the other goes to the Brn/Wht wire.

 

[thumpar]

Re: 1972 120 mercruiser trim guage pegged down

Follow the wires and see where they go from the gauge. It sounds like someone removed the sender and did something with the wiring inside the boat.

 

[Bondo]

Re: 1972 120 mercruiser trim guage pegged down

Hey all, i fixed my idle issue i posted about a wile ago but im also having a problem with my trim guage. My trim works fine but the gauge will not buge from the down position. All my other gauges work exept this one i just dont understand why. It has no sender units on the bell housing but im pretty sure its in the boat towards the left. Could any one point me in the right direction on how to fix this?
Thanks!!!

Ayuh,.... Welcome Aboard,... Bein' a '72, the trim sender oughta be the black thingy next to the reverse lock-down switch,...

It varies the Ground from the gauge,...

Sounds like yer's is shorted out to Full Ground, which equates to full down,...
Open circuit oughta be full Up,...

 

[fishrdan]

Re: 1972 120 mercruiser trim guage pegged down

Ayuh,.... Welcome Aboard,... Bein' a '72, the trim sender oughta be the black thingy next to the reverse lock-down switch,...

Yup, I have the same setup, it's on the starboard side bolted to the transom shield (plate). 2 hydraulic hoses going to it and 2 wires coming out of it. Looks like this;

My trim gauge bounces around during use and I'm under the impression that it's the electrical part of the trim sender that's bad. I haven't troubleshot it, but the hydraulic section seems to work fine as it goes all the way up, just kind of "scratchy" or bouncing.

The electrical portion has 6 screws holding the cover on,,, and I guess I could pull it apart to see what it looks like inside, probably corrosion on the slider, (potentiometer).

 

[180shabah]

Re: 1972 120 mercruiser trim guage pegged down

Useless gauge anyway, take it out and replace it with something useful like a depth finder or a vacuum gauge....