Reply With QuoteI have the diagrams, just trying to figure out which one to scan for you.
I'm starting from scratch on a build... as in, I had a boat with a hole in the transom and I'm assembling a Mercruiser drive. I have all the wires figured out except the ones regarding the trim stuff.
- The boat is an 83 with a Vortec 350 and an Alpha MR T/A and outdrive. The trim senders have four wires (two from each sender) but the gauge has one purple wire. How do I wire the gauge?
- The four power trim wires from the controls (which if I recall are red, green, blue, and yellow?) just end back near where the trim pump goes. (then of course the big power and ground wires from the pump itself) How do I wire the relays with those four wires? If you need to know, its the Gen1 style pump that is high volume, low pressure.
Thanks so much. It would even help if someone just snapped a photo of their pump assembly, maybe I could see what wires go where.
I have the diagrams, just trying to figure out which one to scan for you.
Purple wire on gauge should go to trim sender, right side of gimbal ring. Other wire on gauge goes to ign switch. Second wire on trim sender goes to ground.
I figured something like it but there are two senders, each with two wires for a total of four. I just assumed that one was for the trim part of the gauge and the other was for the tilt part.
the two on the left are for trim limit (only allows drive to trim up as far as switch is set, the rest of the way the tilt has to be used for trailering, etc.)
Can't remember where they plug in at (trim pump or switch up at controls) its been awhile since i did one of those.
jd
Their were a number of variations. But all basically the same. With a gauge on the dash, the trim sender was installed. But some were equipped with a light to indicate trim too. The gauge wiring is simple, as I posted earlier. I will scan some diagrams for the trim pump and control wiring a little later today. The left side is the trim limit, and the right side is the trim sender
Ok, great. Thanks for the info.
Holy crap!!! Be careful when giving advice.If you hooked the purple to the sender, ignition voltage will go to ground as soon as the key is turned on! Purple is ignition power to the gauge which would never go to the trim sender!!! LOOK AT THE BACK OF THE GAUGE. The gauge will be marked on the back. "I" for ignition (purple), "S" for sender (brown/white), "G" for ground (black). The colors I listed are standard Mercruiser wire colors in a factory loom. There are two wires from the trim sender, one goes to ground and the other to the "S" terminal on the gauge. The trim sender is a potentiometer sending a ground signal to the gauge. The trim limit sender wires go as follows: the purple/white from the trim button goes to one of the wires to the trim limit switch (transom) and sends 12v when the button is pushed. The other wire from the trim limit switch (transom) goes to the blue/white wire from the trailer button (handle) AND the plug at the trim pump which then goes to the "up" solenoid on the pump, all blue/white. This wire from the limit switch has two blue/white wires tied together to two different locations.... the trailer button at the dash and the solenoid at the pump. The reason for this is when the "trailer" button is pushed the blue/white bypasses the trim limit switch and allows the drive to raise all the way to the trailer position. I am sure this has totally confused you!!! I can't scan the service manual or I would post it and it would make more sense.
Purple/white is "trim" from the dash.
Blue/white is "trailer" from the dash.
Brown/white is the sender wire to the gauge.
Actually, it didn't confuse... much
I'm not sure about factory wiring, but my ignition wire (in the merc loom) is purple/white, but its pink while jumping around the gauges. The wire on the "S" terminal of the trim gauge is purple/white. Confusing, I know, but that's how it is in my Baja. This is its third engine, second set of gauges, and god knows how many wiring repair patches
So... now that we have that all cleared up, what if I don't have a trailer button? I just have the up/down switch on the throttle. I found a wiring diagram that shows the proper connections (including the trailer button which I don't have.) Should I just not hook up the trim limit switch? Why is it even there? What is it about trimming up the drive that is bad unless its on the trailer?
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