Electrical Help PLEASE! I am thinking there is a bad ground...

Lets start by most all my gauges was bad I replaced the fuel because it was the most important. if I turn my navi lights on the fuel gauge would read and tach would jump to 1000RPMS. As of lately I repowered and found out my heat horn was bad also. Since it is a important piece to not ruining a newly rebuilt engine I replaced it recently then when I turned on the navi lights the horn would chirp but it operated normal other than that one flaw. I since then replaced the tach and water pressure gauge, I was careful to rewire everything back as it was. I went out today as it was going to be a nice enough day to maybe put a few more hrs on the engine. went out to the garage went to trim the motor up and had no juice no lights came on when I turn the switch on or nothing. I was thinking I must have left the key on and the battery was dead tested the battery all was good. Found two loose wires best I can tell they are grounded to the Ground terminal of the fuse box but have no clue where they are suppose to go looks like lots of noodles under that dash wires ever where dont no whats up or down. But heres the kicker in order to trim the motor up the navi lights has to be on and the key switch to on position that is the only way anything will work. I thought about disconnecting evrything getting a manual and starting from scratch. any Thoughts?Sorry this is so long and drawn out but I had alot to say...

Re: Electrical Help PLEASE! I am thinking there is a bad ground...

19V said:

Lets start by most all my gauges was bad I replaced the fuel because it was the most important. if I turn my navi lights on the fuel gauge would read and tach would jump to 1000RPMS. As of lately I repowered and found out my heat horn was bad also. Since it is a important piece to not ruining a newly rebuilt engine I replaced it recently then when I turned on the navi lights the horn would chirp but it operated normal other than that one flaw. I since then replaced the tach and water pressure gauge, I was careful to rewire everything back as it was. I went out today as it was going to be a nice enough day to maybe put a few more hrs on the engine. went out to the garage went to trim the motor up and had no juice no lights came on when I turn the switch on or nothing. I was thinking I must have left the key on and the battery was dead tested the battery all was good. Found two loose wires best I can tell they are grounded to the Ground terminal of the fuse box but have no clue where they are suppose to go looks like lots of noodles under that dash wires ever where dont no whats up or down. But heres the kicker in order to trim the motor up the navi lights has to be on and the key switch to on position that is the only way anything will work. I thought about disconnecting evrything getting a manual and starting from scratch. any Thoughts?Sorry this is so long and drawn out but I had alot to say...

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Been there done that! My solution was to completely rewire the dash using terminal blocks to bring positive power and negative ground to the different systems such as gauges, switches and other accessories. What is blowing your mind is the way things look. I know I have been there. Spent a lot of time with the dash out and old wiring gone putting it back together again and all is well...

Re: Electrical Help PLEASE! I am thinking there is a bad ground...

Thanks! I however was afraid of that.

Re: Electrical Help PLEASE! I am thinking there is a bad ground...

You have a serious wiring issue.
1) the NAV/ANC switch should operate ONLY the bow and stern lights - nothing else.
2) The key should NOT have to be on in order for the trim to work (but since we have no idea what engine make, HP, and year you have we can't be sure of that.
3) The key needs to be in the RUN position for the gauges to work. I can't tell from your description if everything is now working or not.
4) Fix one thing at a time. Trying to diagnose all of the issues as once will drive you nuts.
There are two electrical systems on most boats A) the engine system and B) the boat system. The engine system consists of the big battery cables that go from the battery to the engine. Power and various other circuits then go up the engine harness to the ignition switch and control box. The boat system has two smaller gauge wires at the battery and those go to the console (generally to a fuse panel) where power is then distributed to the swtiches and the accessories they control. The "A" (accessory) terminal on the ignition switch is what feeds power to the gauges. The "B" (battery" terminal on the ignition switch receives power from the engine harness so when the key is on, the gauges come alive. That circuit should not feed the accessory switches which I think is what is hosed up in our case. Look at the "Generic Boat Wiring Diagram" in the stickies at the very top of this forum (not this page). It shows how the gauges and the boat harness is typically wired. For the engine harness you need a diagram in the service manual for your particular engine.

Re: Electrical Help PLEASE! I am thinking there is a bad ground...

I am not sure that the control box has power. The trim should work all the time.regardless of the wacky guages etc. I am going to just have to rol my sleeves and jump into it. I have printed out the boat wiring diagram to help along with the trouble shooting. Wish me luck!

Re: Electrical Help PLEASE! I am thinking there is a bad ground...

You said earlier that the key needed to be on AND the nav lights needed to be on to make the trim work did you not? That says theb ignition has power. Speculating doesn't fix problems. And yes, whacky gauges, whacky nav light wiring and whacky ignition wiring can create whacky trim operation. Get out the tester and fix one problem at a time.

Re: Electrical Help PLEASE! I am thinking there is a bad ground...

Yes But its was getting its power from the fuse panel through the Nav switch which is jacked up!. I have found the main issue. The small fuse that loops off the Big red plug on the engine was blown I believe it is #26 in the diagram. I now have power to the trim and when I turn the key on the gauges come alive like everything should. Now I have to figure out what is wired wacky under the dash and I will be ready to ride once again.