The Boating Forum - gauges flickering

Hi Crew,
I am trying to isolate what wire coming off of a Yamaha ignition would cause the following.

Over the last couple of weeks, I have been working on a console redesign. After completion the redesign/rebuild, I installed new aftermarket guages. I have 4 gauges: Tachometer, Fuel, Volt, and Water Pressure. I wired everything correctly and tested everything after the rewire and everything worked correctly. All gauges performed exactly as required.
I decided to take the boat out today for a test run to make sure everything was running as expected. Upon leaving the dock, I noticed the motor seemed sluggish, kind of like when its in limp mode. Got to the channel, opened it up and nothing. Moved out of the channel and noticed that none of the guages were functioning. First thing that comes to mind is a loose ground. I open the console and noticed some of the connections around the guages were loose...I forgetten to tighten them up :bashhh: Not having proper tools, I finger tightened everything down, checked the guages and everything was operational and motor was running as expected.
So I am left trying to understand what caused the issue.
http://i1172.photobucket.com/albums/r565/jukes231/1b521d59.jpg

Here are the wires that run off the yamaha ignition. There are three wires that are wired in: Yellow is the ignition wire, green is the tachometer (+) and the black one is a ground. So when wiring up the gauges, I chained the iginition lead to the tach, volt and fuel since each of these guages have a post for the ignition. I did the same thing with the ground.

I checked the ground for the motor on the battery and it was tight, so I have isolated it to these two wires.

When I got home, I tightened everything down solid and made sure all female/male connections were tight.

My question is, was it the ground or the ignition? The leads for the iginition harness to the guages was pretty tight, so I am not sure if the ground was acting up, would it set off the guages.

Anybody have any thoughts? Also, would it make sense to ground the ground wire coming from the ignition directly to the grounding block or leave it in the grounding harness as described above.

sorry for the long post, any help is always appreciated.

Joe

O.K. - I had a very similar problem a year ago or two. My gauges were flickering and the motor would lose power and sometimes stall. I had a loose ground wire on my Yamaha engine block. This is the heavy gauge cable from the battery. My positive was loose too. I added stainless steel lock washers (which should have been there but were not). Disconnect your battery before you put a wrench on the positive lug at the engine. Good luck.

O.K. - I had a very similar problem a year ago or two. My gauges were flickering and the motor would lose power and sometimes stall. I had a loose ground wire on my Yamaha engine block. This is the heavy gauge cable from the battery. My positive was loose too. I added stainless steel lock washers (which should have been there but were not). Disconnect your battery before you put a wrench on the positive lug at the engine. Good luck.

DrewC, Thanks for the reply. That was my thought initially, but I checked the fittings there and everything was solid. None of these have been touched, other than when I disconnected the batteries during the rewire. I made sure everything was solid in the battery compartment. Plus, when I tightened up whatever was loose under the console, it stopped. I never touched anything in the battery compartment.

I am really trying to figure out whether it was the ignition ground (black wire) or ignition positive (yellow wire) that caused the issue. Both wires are directly wired to the gauges, so it could be either one.

My money is one the ground, just not sure at this point.

Thanks,

Joe

Anybody?

I did some more trouble shooting and noticed that the key has a little play in it. if its wiggled a little to the left (to shut it off) or to the right (to start the motor) the guages stop working, but the motor still runs.

Should the ignition have some play in it? Also, I lost my regular key (the one with the black cover) and use the spare key.

If I have to replace the ignition, does anybody have the yamaha part number for a 704 ignition?

Thanks,

Joe

Another quick update:
I checked all of the wiring in the guages to make sure nothing was touching so that things were shorting out. nothing was touching. So without starting the boat, I simply turned the key to on and watched. the gauges flicker a little at first, but that goes away. I keep thinking bad ground. I rerouted a new wire from the battery to the grounding block and same result. I did notice that if I wiggle the key to the left and right, I can get the fuel and volt meter to bounce around. the tach will do the same thing if the boat is running. This will also cause the buzzer to go off.

At this point, I am seriously thinking its a bad starter switch assembly. The rubber grommet covering the key hole fell off a few years back so chances are, there could be some corrosion inside.

Just wasnt aware the buzzer would go off due to a bad ground.

Any thoughts? anybody?

Did you check the ground wire at the engine block? Not the battery connection in the boat, but the large postive and negative connections on the side of the engine block. That's where my loose ground was. The engine vibrations loosened up both of these.