[jwpilger]

1990 Bowrider 1850XL just bought from a friend and all the dash guages work but some of the navigational, accessory etc. switches cause problems. When the boat motor (alternator) is running, all is well. On land with only battery, I turn a switch on and none of the other switches work??? I have swapped two of the 12V switches for new ones form custom marine supply and still have the same problem. I see the dashboard power switches are in a series and have checked switches, fuses and connections etc. Everything looks okay and works fine until randomly one switch fails and dash guages go to the right indicating a short circuit? When I start the boat all is well. Starting the boat seems to reset the shorted circuit and all works well, even on battery, until I use one switch and back to failure mode.

Any thoughts on how to isolate this problem?

[WetWilly]

Hi jwpilger,

I must say, you've definitely got a odd issue in deed... but we're going to try our best to fix it!

Assuming the previous owner didn't change any wiring around, I would say it seems like you have a resistance problem (corrosion?) in the positive wiring to the gauges probably at a common junction or the ground between the block and the negative battery terminal. Would you mind doing me a favor, if you have a Volt Meter, could you check the voltage at the positive terminal on some of the gauges when on battery power, especially when they're going crazy and again with the motor running and they're working fine?

Thanks,
WetWilly

[jwpilger]

Thanks for the guidance. I'll check the voltage this weekend.
Any suggestions on removing visible rust or corrosion on electrical connections or components?

[WetWilly]

I find a Dremel and a steel wire wheel works wonders on the rust and corrosion! Just remember to use eye protection!

WetWilly

[jwpilger]

I used my voltmeter to test voltage when all is working fine and when the dash circuits fail. Normal conditions, voltage at the battery and guages are the same - 12.6V. When in the problem state, voltage cycles from 11.3 to 11.8V. Other items on independent circuits (radio) work fine. I'm still not sure why everything works fine such as when the engine is running and continues to work until one dash switch is used then back to nothing working???

[Cj7]

You have the correct voltage it sounds like, so to me the problem would be a ground... Like wetwilly stated check all connection! The grounds are the most important and will be the likley suspect.

Cj

[jwpilger]

Well, you were correct. The dash guages and switches are serially connected with the same ground wire. When I remove cig lighter ground wire and connect it to the steering bar, everything works great. Thanks for the advice.

Any thoughts on how to correct? The after-market radio was grounded to the steering bar. Should I do the same with the nav lights and dash guages? It difficult to trace the ground wire back to it's origin.

Any insight will be appreciated.

[Cj7]

The ground is going to have to go back to the battery or the engine block which is hooked to the battery. The steering post is not a good location for a ground unless it is hook to the battery. The electricity need to make a loop back to the battery and fiberglass is not a good conductor which is what your steering post is hooked to.

Good Luck
Cj

[barberw]

Originally Posted by jwpilger

1990 Bowrider 1850XL just bought from a friend and all the dash guages work but some of the navigational, accessory etc. switches cause problems. When the boat motor (alternator) is running, all is well. On land with only battery, I turn a switch on and none of the other switches work??? I have swapped two of the 12V switches for new ones form custom marine supply and still have the same problem. I see the dashboard power switches are in a series and have checked switches, fuses and connections etc. Everything looks okay and works fine until randomly one switch fails and dash guages go to the right indicating a short circuit? When I start the boat all is well. Starting the boat seems to reset the shorted circuit and all works well, even on battery, until I use one switch and back to failure mode.

Any thoughts on how to isolate this problem?

I have been out in my boat the week end and had a intermittent elec problem. I have found that the fuse holders are not tight which is giving me this problem so i need to have a look closer or replace the fuse pannel
My boat is a mariah 180 3.0l I dont know if this will help but might help others in the same sitch

[Robert Stocklas]

I have same problem, where did you get new rocker switches from, can't seem to locate what I need for my Navigation light switch.