How does a trim gauge work 86 mercruiser?

[lime4x4]

I replaced the trim sensor and trim limit sensor on a 1986 mercruiser alpha drive. I got the trim limit set properly. I'm having a hard time getting the gauge to respond correctly. When the drive is all the way down it shows D on the gauge. When i trim the unit up till it stops (trim limit) it shows UP. The needle doesn't gradually go up.Just as it reaches max trim it jumps to UP. Then if i use the trailer button to bring the drive all the way up It shows DOWN

 

[Don S]

Re: How does a trim gauge work 86 mercruiser?

Sounds to me like you have the trim limit switch hooked up to the gauge and the gauge sender hooked up to the trim limit wiring.

 

[lime4x4]

Re: How does a trim gauge work 86 mercruiser?

Thats what i thought at first. But the trim limit uses 1 female plug and 1 male plug. Plus if that was the case i wouldn't be able to set the trim limit correct?

 

[Don S]

Re: How does a trim gauge work 86 mercruiser?

Then test both senders with an ohm meter. The trim limit is a switch off (no continuity) or on (continuity).

The gauge sender should evenly increase and decrease in ohms as you turn the sender.

 

[bds85466]

Re: How does a trim gauge work 86 mercruiser?

There's obviously something odd about your positional wiring. I believe the trim position is a potentiometer, so it should give out a signal that varies as you move up and down (not strictly high or low like you're experiencing).