My boat used to have a procharger on it. It was taken off by a previous owner. I still have the boost gauge and fuel pressure gauge on the dash. They are gaffrig gauges. The boost guage just has a hose going to it which is diconnected and a white and black wire. The fuel pressure guage has a red, black, white, purple, yellow and green wire to it. I am assuming these guages are disconnected but still have power to them because when I turn the ignition on the needles go all the way to one side and the back lights come on when I turn on the running lights.

I want to remove these guages from my dash. To fill the two holes I will install a clock and a wired stereo remote. I have purchased a Faria clock and I am not worried about putting in the wired remote. The problem I have is that I am nervous about removing the wires from the fuel pressure guage. The clock I purchased only has a ground connection and a power connection, and a clip to hook up the back light for night time viewing. Removing the boost gauge seems simple because the wires for the boost guage are "jumped" from the fuel pressure guage.

My question is how do I or what wires (colors) do I go to the clock with? And also which wire do I use for the back light on the clock. I will give the two gauges free of charge (shipping included) to the person who can help me with this. Thanks in advance for your knowledge. Eric

You can call gaffrig for the exact wiring, but I installed the same gauges last summer. The fuel pressure has 6 wires 2 for backlight 2 for power and 2 for the sending unit. Each of these pairs includes one ground wire. You can figure it out with a simple test light. Find the ignition light with the key on then the backlight with the lights on and forget about the sending wire. I'd check my gauge wiring for you but my boat is packed away right now.

You will need a constant 12v source for the clock, I woudl imagine (otherwise it will need resetting every time you turn off the power).

Red is hot all the time. (Hook clock power to a red wire)
Black is ground.

Dk Blue is for lighting power if the clock has a separate terminal for this.

Purple is hot only when key is on.

Those are the standard dash wire colors. Sounds like a couple of the wires you listed are add on, for sender no doubt. Might trace the wires from the pressure gauge and see if they don't tap onto original wires.

The clip is more or less a 'jumper' from the main clock power terminal to the light terminal. When the clip is used, the light is on all the time. By removing the jumper clip and then connecting the lighting terminal to a dark blue wire, you only back light when dash lights are turned on.



Gaffrig fuel pressure gauge connection

US1 Fountain - It sounds like all I need to do is hook up the red to the hot on the clock and the black to the ground.
As far as the backlight, I don't have a separate lighting terminal, all thats there is just a jumper clip. If one of my other gauges has similar a clip, can I just tap into one of those (by this I mean splicing into the wire and going to my clock also. I would suspect that since all of my other gauges are Faria, that they would have the same type clip for lighting as the my Faria clock and that I could just splice off of one of those, if you think that would work. I am not worried about losing power to the clock when the key is off, because when I put my boat away for the night I always turn the battery switches to off so there is no power to anything. I can deal with resetting the clock each time I use the boat. I know it will be a pain but really all I am looking to do is fill the hole in the dash where my boost and fuel pressure gauges were, but I still want the clock to be functional even if you have to reset it each time you turn the juice off.

Also as far as testing these wire to see which on is hot, could I use a glow stick that you use for house wiring, because that is all I have. Or do I need something else?

Red and Black wires.....Yes, but then the light will be on all the time too. You need to separate the main power terminal from the lighting terminal by removing the clip so light is not always on.
You should have a Dark Blue wire connecting all the gauges that are back lit in series. You want to connect the spade if you can remove the jumper clip to anywhere on the Dk Blue wire. The DK BLue is the standard Merc dash lighting wire.

You may have a condition were the previous owner did not follow suite on wire colors when installing the pressure gauge, but you should be able to just follow them to point of connection and determine what is what.

you should only need 3 wires. Red (for constant power), Black (ground) and Dk Blue (for lites)


I don't know if the glow stick will work on 12v. I think it should. Can always check it accross the battery terminals.


See if this helps........

Faria clock wire diagram

Normally you should be able to go from the power terminals on the other guages. I would not recommend splicing wires if at all possible. If you want help I am in the St. louis area.

Forrest
You are right, I should have been more clearer about tapping onto wires only at terminals. Can't use the power terminals from other gauges though as they will be switched power. Pull full time12v from any dash switch.

Jerry

Jerry and Forrest - Thanks for the tips. I will investigate to see if the Gaffrig fuel pressure gauge has a blue wire, I would think it would because it lights up when I turn on the Nav lights. I may have overlooked that. It sounds like I can just find a blue wire from another guage terminal and run it over to the clock. I will be at LOTO on Friday to try the installation. I think it may be pretty simple now. The only thing that baffles me is that when I pulled the dash to look at the wires going to the booster and fuel pressure gauges last Friday is that it looks as though Graffrig has a white and a black wire going to the lighting portion of their guage. This is what confuses me.