Trim limit switch wire confusion

Datimm

Seaman Apprentice
Joined
May 8, 2019
Messages
31
I just reinstalled the 3.7 in my boat and I am reconnecting all the wiring, but I am lost as to where the second trim limit switch wires go. The bullet style connectors are plugged into the harness but the second limit switch has eyelet connectors that I am unsure where to put. Any help would be appreciated. 20190619_214448-1701x3024.jpg
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
If the wires come from the drive then they should be used for the trim gauge. One goes to the gauge and the other goes to ground
 

Datimm

Seaman Apprentice
Joined
May 8, 2019
Messages
31
Could these wires being disconnected stop my power trim from working? I have down but I can not get it to go up.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
They might, I haven't been around a 470 much. The newer model trim design uses 3 wires (main power, up and down), and the pump is grounded. The double blue/white would go to the trim limit switch on the drive, and the other side would go to trailer up function. The trailer switch is used to bypass the throttle handle switch.

With not getting up function, it could be the other wires need to be connected and one may be ground. Don't know if you have 2 trim relays or just 1

This is the newer wiring which uses 2 relays

Trim wiring Merc 2012.jpg
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,033
Try using your "Trailer" button to trim the outdrive up. If that works, chances are that the trim limit switch is broken.

On my '88 MerCruiser the trim limit switch and trim position sender were on the pivot points of the outdrive, and open to saltwater. They didn't last long....
 
Top