Texas Fishing Forum

Wiring. Please help. Purple accessory wire.

Posted By: G Pope

Wiring. Please help. Purple accessory wire. - 11/24/16 02:06 AM

Not sure what happened.

Recently my fuel gauge went out. Was showing empty at all times. Following the wires from the gas tank to the gauge as best I could, I noticed that the wire leading out of the gauge fed into the ignition switch. Wile checking all of this I found a single purple wire unconnected in the back of the boat in the battery hold.

Just testing around, I touched this wire to the positive post on one of the batteries the fuel went past full. I connected it to the 2nd battery and ALL of the gauge lights lit up, but the fuel gauge stayed on empty.

I can not find where this wire should connect and there is not another wire that appears to go with it. (Positive/ground). Feels kind of like I am hot wiring my boat in order to start it. Certainly will not be getting on the water until this issue is fixed.

Hooked up to the battery that moves the fuel gauge, turning the key does nothing.
When hooked up to the battery that lights up all the lights on the dash the engine will turn over.
Leaving the wire alone unconnected I get no power to start.

I am sure this got disconnected from some where while was chasing wires around. Now the boat will not start unless I connect the wire to battery that lights up the dash.

How this makes sense and someone can help. Any advise is greatly appreciated.
Posted By: Bob Landry

Re: Wiring. Please help. Purple accessory wire. - 11/24/16 02:24 AM

Unless someone has shade-treed your wiring, purple is always switched 12V from the ignition. The pink wire is from your fuel tank sending unit and you need a ground.

If you can post the manufacturer of your fuel gauge, one of the mechanics on here will probably be able to tell you what wire goes to what terminal on the gauge.
Posted By: gary purdy

Re: Wiring. Please help. Purple accessory wire. - 11/24/16 02:59 AM


Hooked up to the battery that moves the fuel gauge, turning the key does nothing.
When hooked up to the battery that lights up all the lights on the dash the engine will turn over.
Leaving the wire alone unconnected I get no power to start. Connect to battery that the gauge lights come on and move the small black grounds on the first battery that moved the fuel gauge to the battery that lights come on. You should have all working. Check to see if the Nav light switch is turned on.
Posted By: G Pope

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 04:52 AM

2009 Nitro x5

I can not find a black ground wire from the dash to the battery. If I could determine that and get on the same battery, I think I would be in business.
Posted By: TLW

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 07:06 AM

1 battery should be for motor start and all acc.. ie: fuel gauge, lights, gauges, depth finder and etc at console.. should be ONLY power to console stuff/ign switch... other battery/batteries for troller only unless someone has used some southern enginnerin'.. purple is a switched hot (key on).. purple is hot to fuel gauge (key on), pink is sender (tank to fuel gauge).. blue is gauge lightin'... black from same battery for "everything" at console and lights... thats tha way its "supposed ta be"....
Posted By: gary purdy

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 01:16 PM

Then run a wire.
Posted By: Bob Landry

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 01:54 PM

You are not going to find a black wire going directly to the battery. It's going to be imbedded in the engine wiring harness. As Gary said, there is no problem running a wire back to the battery as long as you connect to the engine battery and not the aux one.
Posted By: G Pope

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 07:16 PM

Checked the lights. They work when the main power switch is turned on, and go off the power switch is off. The dash lights still run at all times when the purple wire is connected to the battery. Key in or key out.

Seems like the wire should change nnected upstream before the battery somewhere so when you turn the key it gets power. Connecting it straight to the battery gives it power at all times.
Posted By: G Pope

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 07:18 PM

Also thanks Gary and Bob for trying to guide in the right direction. I am not an ignorant person, but I feel like one in this situation. Electrical work is not my forte.
Posted By: Bob Landry

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 08:25 PM

I'm concerned with a purple wire connected to the battery. It should only have voltage on it when the key is in the on position. Otherwise, what is normally turned on and off with the ignition key would remain on all the time since it would always see 12V.
When you refer to lights, are you talking about the instrument lights or navigational lights. If instrument lights, then they can be wired two different ways. One, when the ignition key is on and two, they can be wired to the switch that turns on the red/green/white navigation lights since you wouldn't need instruments lights unless it's dark enough to need running lights. Either way is acceptable, but the wire that is normally 12V switched(purple) should not be directly connected to the battery, unless as I suggested above someone had shade-treed your console wiring. You might do will to pay a shop to sort it all out for you.
Posted By: gary purdy

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 10:29 PM

Take the purple wire and connect it to the Nav lights switch`s anchor light post, If not connect it to the main power switch. Like Bob said the purple needs to be on a switch.
Posted By: TLW

Re: Wiring. Please help. Purple accessory wire. - 11/25/16 11:54 PM

tha purple should "orginate" at tha ign. switch and fed hot by tha red when in on position.... should be a joint made (usually) close to tha switch with a purple that goes in tha harness back to tha motor and one that should go to fuel gauge, over heat buzzer and tach if so equipped... should be a completely separate red and ground that powers everything else through a fused board, inline fuses or breakers that's tha "normal" way......

here's tha switch and harness showing tha only things that it concerns.

http://graph.darren-criss.org/2016/02/10/mercury-outboard-key-switch-wiring-l-24c5efed57eea4e4.jpg

Posted By: Bob Landry

Re: Wiring. Please help. Purple accessory wire. - 11/26/16 12:22 AM

Somewhere in that engine wiring harness there should be a black wire which is ground. I didn't think about it but TLW is correct, the only ground going through the ignition switch goes back to kill the motor. If you need to run a ground wire from the console back to the battery, there is no problem in doing so. Ground is ground and is the same electrical point regardless of where you check it. The important thing is that it go back to the engine battery. Getting ground off of the aux battery for instruments on the console can create some really interesting problems. Don't ask how I know. Also, double check that the purple wire only has 12V when the key is on and goes dead when you turn it off. That is how all of the console instruments are turned off. You don't want 12V to them all the time.
Posted By: G Pope

Re: Wiring. Please help. Purple accessory wire. - 11/26/16 05:07 PM

Some progress made, I think. I have identified a ground wire that when connected to the start battery, with the purple connected to the start battery the fuel gauge spikes to full and the gauge lights all light up. Connecting to second battery does nothing now.

This ground wire was connected to the second battery before which is why I was getting 2 different results previously. I agree that not being connected to the start battery was part of the issue.

Only remaining issue is that all gauges light up while connected directly to the battery. I can not find a switch in the back of the boat. The purple wire was certainly connected in the back somewhere before. Should it be connected upstream to the motor power, or before it feeds back from the motor to the battery? I assume the ground connects directly to the battery also.
Posted By: TLW

Re: Wiring. Please help. Purple accessory wire. - 11/26/16 06:14 PM

now that you found tha right ground leave tha purple disconnected in tha back.. turn tha key on and see iftha fuel gauge works..... that purple is supposed to get its 12v feed from tha on position of tha ign. switch.. no where else.
Posted By: spankyttx

Re: Wiring. Please help. Purple accessory wire. - 11/26/16 07:04 PM

touching that purple wire to a power source back fed 12v to the ign switch, yes everything is gonna come on on the dash
Posted By: Bob Landry

Re: Wiring. Please help. Purple accessory wire. - 11/26/16 09:08 PM

Again, if you have 12V on a purple wire anytime other than when the key is on, it is wrong, connecting it to a battery to see what comes on doesn't tell you anything.
Posted By: G Pope

Re: Wiring. Please help. Purple accessory wire. - 11/27/16 03:14 AM

Nothing works when the purple wire is disconnected and the key in the "on" position. No trim, no start, no fuel, no power. At this point I have always on or disconnect and nothing.
Posted By: TLW

Re: Wiring. Please help. Purple accessory wire. - 11/27/16 04:49 AM

ya definitely have something very wrong... TnT should work 24/7 as long as ya have a battery in it... even without a key in tha ign, much less turned on........
Posted By: hopalong

Re: Wiring. Please help. Purple accessory wire. - 11/27/16 01:43 PM

have ya checked you fuses/breakers? sorting wires it is easy to pop one, ask me how I know.
Posted By: hopalong

Re: Wiring. Please help. Purple accessory wire. - 11/28/16 02:39 PM

you need to email nitro/bass pro and have them send you a wiring diagram for your boat, then you can start tracing the problem.

nickle and dimeing an electrical problem is pretty much an effort in futility.
© 2024 Texas Fishing Forum