Weird electrical problem

[imanavyflyer]

I have a 1996 SeaRay 175 BR, 135 Merc I/O. Runs fine. It's been a few months since I fired her up. She started fine, I was going through some TLC stuff before putting her in the water, making sure everything works, topping off fluids, etc. All the electrical stuff works fine, BUT, when I turn on the running lights, the needles on the oil press, temp, rpm guage, battery guage, jump up a bit and then creep high...no change in engine noise whatsoever (even though rpm needle goes up). I'm guessing it's a short of some kind or maybe a sending unit(?). Also, the backlights for the guages do not come on. Pretty sure I may have to chase down a short, but I just thought I'd post my story to see if I can narrow the search. Thanks!

 

[snapperbait]

Re: Weird electrical problem

I had this happen to me once before, but I can't nail down exactly what the culprit was (Brain Fades out sometimes, ya know?)...<br /><br />My first instinct would be to check the negative poles and circuts of the gauges for poor connections...

 

[EatMoreFish]

Re: Weird electrical problem

yep sounds like a bad ground somewhere

 

[SlowlySinking]

Re: Weird electrical problem

I agree on the ground problem, however if that isn't it consider this, I'm not sure about a boat but most guages operate on less than 12 volts through a voltage regulator, same as in a car, if the regulator goes bad the guages either all quit or they can act like tachs as you rev the engine and the system voltage goes higher and they read higher. You probably need a manual with wiring diagrams to verify the existence and location of a regulator. Good luck,

 

[magster65]

Re: Weird electrical problem

I bought a boat that had sat for about 7 months without being used. I had conflicting information from a few duplicate guages (bridge/interior). I never did find out what it was but the problem went away with a bit of use. All the connections look clean and corrosion free. I've wondered if the bridge guages got some moisture in them somehow and having the guage light on dried it out?

 

[AndyL]

Re: Weird electrical problem

Just a guess, but years ago on a commercial high speed twin engine boat we had a problem in the controls lighting circuit that would intermittently cause all sorts of problems, including randomly clutching an engine in!! Since the only common circuit between the two engines was the lamps, it was eventually traced down to an earth on that circuit. You could also check that the bulbs in the circuit are all the correct wattage/ voltage as this could draw down more current from the overall feed and hence cause the instruments themselves to mis-read.<br />Good hunting!

 

[imanavyflyer]

Re: Weird electrical problem

Hey thanks everybody for the replies!! Nice to be involved in a great community! Anyway, I fixed it last night (for now). Got under the console and looked closely at all the connections, all were secure, none of them were touching eachother, etc. I jiggled a couple, etc. I noticed (unless I'm mistaken) all the guages had a blue wire connecting to it (although not in series) This wire went to all the guages and between guages, which I'm assuming was power for the bulb (what do they all have in common.) I removed the bulbs and cleaned the contact points, and WAH-LA!! It works fine. Sooo, I don't know whether I jiggled the correct wire or, the contact cleaning on the bulbs did it, but it works for now. Either way, it probably was corrosion in some shape or form that was making some sort of connection somewhere (or blocking a connection that it shouldn't have)<br /><br />See you on the water and thanks again!<br />Bob

 

[Kesh]

Re: Weird electrical problem

Lol, I started to read the messages and immediately came to my mind that running lights switch also powers up the lights of the gauges, so the problem had to be related to the lights of the gauges. Then I saw the post where manavyflyer says the problem is solved. Anyways, in my boat there is a blue wire with positive 12 volts which comes from the running lights switch. The blue cable feeds the first gauge bulbe light and then there is another piece of blue wire going to the second gauge...and so on.