1980 Merc Trim Wire...Where does it go?

[Merlin509]

I have a 1980 Mercury 90hp that has a wire not connected on the Trim/Tilt harness and I don't know where it goes. The trim/tilt seems to work okay, but I'd like to make it right. The wire is brown with white stripe and part of the four wire harness coming off the back of the controller. Picture below:

 

[Chris1956]

Are you sure it is part of the PTT harness? Normally you will have the two battery cables and the three connector plug, on the PTT pump/reservoir.

Normal colors of the wires are 2 red, 1 black, 1 green and 1 blue. Brown/white could be a trim gauge sender, although I did not think they had one in 1980.

 

[sam am I]

The book (to early 80's) says that the "brown w white stripe runs from the trim sender to the trim gauge" From the photo, that looks like the gauge side ring lug that would hook to the "s" terminal on the back of the trim gauge.

I assume you chased the other side down to the sender? If you have an ohm meter, hook one side to the ring, the other to ground and run the motor up and down and watch the meter.........should be something like 170 ohms full up to like 10 ohms full down.

 

[Dukedog]

Are you sure it is part of the PTT harness? Normally you will have the two battery cables and the three connector plug, on the PTT pump/reservoir.

Normal colors of the wires are 2 red, 1 black, 1 green and 1 blue. Brown/white could be a trim gauge sender, although I did not think they had one in 1980.

tha 3 wire "plug" on that one is right below tha one solenoid .. ya can also see tha blue, green, purple/white, brown/white make up a small TnT harness... pretty sure its period correct..

 

[Merlin509]

Looks like it is for a trim gauge. I get about 165-175 ohms across it when activating trim. Not sure why it's back at the trim motor, though.

 

[sam am I]

yes, lil weird to be back there if it is what we suspect.....But, the 170'ish sound about right.

 

[Merlin509]

I'll just run it up to the front and tie off for now. Thanks for the help!

 

[Dukedog]

might check... think that little four wire harness (green/wht, blue/wht, purple/wht, brown/wht) should at least go to tha control box or dash/console for trim buttons... it does on some in those years..