View Full Version : Electrical issues

06-04-2006, 02:12 PM
I have a difficult problem to find. My 2000 Mobius V has been randomly stalling. It may run for 5-10 min, if I watch the gauges I can see the voltage will normally read abou 13.5 V, but before it dies it is between 10-11 V. Once it dies, I have to reset the breaker on the Integrated Circuit board breaker, 20A. If I wait 2-3 min it will start up and run again for a minute the quit again. I need to let it sit for at least a 1/2 hour for it to run any amount of time again.

I've searched the board and read about the Medallion 1600 controller, but I don't think I have this, I can't see it anywhere and I have the paddlewheel speedo. I've kept a voltmeter on the battery when it dies and it does drop down to 12 or so on the voltmeter right before it dies. I've tried swapping batteries but that also did not help. When it's running good voltage is between 13.8-14V

I'm suspecting a bad ground, but don't really know where to start. Right now I have all accessories on the Integrated Circuit board disconnected so only the wiring harness and gauges are getting power, but it still dies. One thing I did notice is that when I trace the voltmeter back it gets it's power from what appears to be the Accel Coil. Just running on accessory battery power every power source I test is at 12.32 V, but the grey wire for the voltmeter off the coil is 12.21. Does that mean my coil could be bad or should there be some resistance here?

Any help or troubleshooting steps would be very much appreciated. I hate electrical problems!! I hate docking without power even more :)

08-16-2009, 04:17 PM
i think i have the same issue

08-17-2009, 11:39 PM
I have now run into the same problem. My boat will run fine, but I can only do one thing at a time. I can not run the pups while the engine is running or perfect pass shuts down, and all of my other accessories do the same thing. I can not get the voltage above 11.5 volts. I have replaced the ground, battery and alternator and the issue remains. Has anyone else seen this problem and could help us out?

08-17-2009, 11:53 PM
Where is the voltage regulator on these alternators?

08-18-2009, 01:38 PM
Honestly, I don't know. On my 02 there are 4 connections, one for the positive, one for the ground and a two prong plug that goes into a loom and dissapears. I am extremely baffled on the electrical issue that seems to be happening to my boat as well as the other boats in this thread.

08-18-2009, 11:25 PM
A voltage regulator is what determines the output of an alternator. When the system voltage drops this signals the voltage regulator to bump up the output of the alternator. OK I am not a EE so you would have to check out wikapedia to see how it works, but it increases the feild strength of the permanent magnets or something to that effect to increase the voltage output.
Anyway, I have seen people replace alternators for a few reasons when they probably could have fixed it themselves.
1.) The alternator itself has to be grounded, on some old cars the alternator was mounted directly in a steel bracket so that would make a ground. On many new Bosch alternators (this is what I am familiar with) they are mounted in rubber so there would be a separate ground strap from alternator to block. This little strap would often break or the nut would back off on one end or the other. Check this with an Ohm meter!
2.) The second most common reason was a bad voltage regulator which again in my experience is a small module attached to the back of the alternator. Again on the Bosch units you can purchase this separately for much less than the complete alternator.
3.) Slipping belts, you wouldn't believe how often I have seen this, proper belt tension is a must. I am guilty of this one because I never wanted to put to much a load on the bearings so I tend to not tighten them enough. And you won't always hear them squeal!
4.) Worn out brushes, OK I can't see this as an issue on a ski boat, for over 22 years I ran the same alternator on the old MC and never had it rebuilt or replaced. I did have to replace the voltage regulator a couple of times during this period. But we don't put the hours on a boat like you do a car.
Finally, if the alternator is suspected and you don't want or know how to deal with it and you can get it off yourself take it to a Starter/Alternator repair shop and I don't mean Pep Boys. Go to a pro and save yourself a bunch of money!!!

08-21-2009, 05:51 PM
You can use a voltmeter to check your ground. Hook the positive from the meter to the battery. Ground the negative to your: block, then alternator, then to any negative busses. All should read what the battery when tested by the voltmeter reads.

I assume that once the boat dies, and then you start it back, that you need no jump off and that your boat volt meter reads fine until the problem starts, as you have illustrated.

I would suspect a bad connection between the alternator and the battery, or the alternator to the positive bus that it feeds. Some simply feed to the starter and link up with the positive coming from the battery.

If you have a perko switch, then sometimes you have to check the nuts on the connections as they will loosen up, or sometimes were not really that tight to begin with.

You can also check the resistance between connections. Say, the resistance between the negative on the batter and alternator body.

08-23-2009, 12:44 AM
Found my electrical issue today!!! I took my volt meter out to the lake today and started hunting gremlins. This is what I found, I had 14 volts at the battery and 11 volts at the dash. I checked the ground by putting the meter on the dash and the battery and everything checked out again, there was a good ground according to the meter. So my buddy Tommy and I started tracing wires from the dash back to the engine and low and behold we fell across the issue. On my 02 there is a large 6 to 8 prong plug that connects to a breaker looking box just to the right of the distributor and above the starter. When we looked at it, we realized that the plug was only about half way in, so we gave it a firm push and it moved a good bit, about an 1/8 inch or so. We fired the boat back up, turned on everything, pumps, stereo, light bar, blower and the navigation lights. The guage was reading 13.5!!!! No more 11 volts and beeping perfect pass, what an easy fix. I must have knocked it loose installing the new ballast valves which work wonderfully!!! Hope you other guys find somehting as easy as I did.