Erratic voltage - please help!

KentBoyle

Cadet
Joined
Feb 3, 2004
Messages
29
I just got back from the lake. After motoring at WOT for a couple of miles, we stopped to eat our dinner. I went to turn on the depth finder, and noticed that it wouldn't turn on - also, the radio would turn on, then turn off immediately. I tried to start the engine, and it would fire and run for a second, but it would bog down and stall, even if I gave it throttle. Also, during this time the tach started to creep up - it went from 1,000 to 4,000 even though the engine wasn't running.<br /><br />I waited about a half hour, and tried to start it again. This time it started, although the tach was at 2,000 throughout the whole throttle range. For kicks, I tried the fishfinder again, and it turned on. The voltmeter in the fishfinder was registering 14.4 volts with the engine running. If I turned on another electrical accessory (radio, light, etc.) it would drop to 13.4. With the engine off, the battery is at 12.4<br /><br />The tach started working again, and I ran the boat another hour or so. Any idea what my problem could be? I hate intermittent problems like this, it doesn't give me a whole lot of confidence in my ability to get back to the ramp.<br /><br />Thanks for the help.<br /><br />KB
 

KentBoyle

Cadet
Joined
Feb 3, 2004
Messages
29
Re: Erratic voltage - please help!

I should also add that this is a 1998 115 V4 Crossflow. The powerpack, and coils are new this season.
 

DHPMARINE

Captain
Joined
Dec 16, 2003
Messages
3,688
Re: Erratic voltage - please help!

Jade89,This may not help,but should be done to EVERY boat with a battery.Tighten those wing nuts with pliers.<br /> You might also check the other ends of the wires at the engine.A power pack and 4 coils in the same season?<br />DHP
 

KentBoyle

Cadet
Joined
Feb 3, 2004
Messages
29
Re: Erratic voltage - please help!

DHP - The powerpack and coils were replaced while chasing erratic idle problem. It gets expensive to fix problems this way, that's why I was hoping to be able to tackle this one a little bit more directly.<br /><br />SoLittle, am I looking for on the switch? Continuity? A bad ground?
 

KentBoyle

Cadet
Joined
Feb 3, 2004
Messages
29
Re: Erratic voltage - please help!

Does anyone else have any ideas what could cause this?
 

KentBoyle

Cadet
Joined
Feb 3, 2004
Messages
29
Re: Erratic voltage - please help!

I've decided to try replacing the switch. I just took the old one out, hoping there'd be a part # on it somewhere.<br /><br />Does anyone know the part # for this? It has five slotted terminals, and one round terminal. I've attached a picture. The terminals are labeled: C A M B M S<br /><br />Thanks.<br />
switch.JPG
 

voodoo

Petty Officer 1st Class
Joined
Jun 23, 2004
Messages
258
Re: Erratic voltage - please help!

It has been said here that the tach is the voice of the rectifier.
 

IPM

Recruit
Joined
Aug 23, 2004
Messages
3
Re: Erratic voltage - please help!

the errattic rpm gage is indicative of a failing voltage regulator for my 1996 115 V4. Perhaps the same applies to yours as well?
 

KentBoyle

Cadet
Joined
Feb 3, 2004
Messages
29
Re: Erratic voltage - please help!

I seemed to have solved the problem - either that, or it went into hiding...<br /><br />I sanded both ends of the main grounding strab which bolts to the block. I also took the ignition switch out and sanded the contacts and all the wires that attach to it. The couple times I've used the boat since then, the problem didn't seem to affect it.<br /><br />Thanks for the suggestions!
 
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