Low Voltage Warning - Boat will not get up to speed....

[Chad52]

Sunday, a friends Nautique had the starter go bad and I had to tow him back into the marina. We were quite ways away and I probably pulled him 5-6 mph for well over an hour to get back to the marina. While I was towing him, the audible low voltage alarm periodically beeped at me and the analog voltage gauge was showing about 11 V. I didn't worry about it too much because I just assumed that I was turning enough RPM's for the alternator to charge like it should. I had the radio cranked and we just basically enjoyed the ride in. After getting him all trailored up, I left the marina to meet some friends and when I went to throttle up, everything felt fine until I got to about 11-13 mph (still not planed out) and thats as fast as it would go. Even at full throttle, I couldn't get the engine to get up to speed. I thought I might be in "limp mode" although I'm not really sure how "limp mode" behaves. At this point, the digital low voltage alarm starts flashing. I cut everything off to just let it set for a bit (about an hour). When I started it back up (I never had any problems getting the boat to start), it behaved exactly the same way. I started the long ride home going about 3/4 throttle and only able to go about 11-13 mph. If I ran any other electrical items, the low volatge alarm would flash. it was telling me I was still between 11.8 and 12.2 volts though. After about 20 minutes, the throttle started creeping up and eventually I was able to get on plane. Once on plane, I could accelerate and drive like normal, ~35 mph. I didn't experience any backfiring or otherwise unusual behavior. The low voltage alarms were both sounding though.

So any ideas what might be going wrong here? can you fry an alternator from running in the manner that I described here? I think I will pull the batteries tonight and take them to get them checked, but I was wondering if anybody might have any insight to what happened.

Thanks,

Chad

[Rick]

RE: Low Voltage Warning - Boat will not get up to speed....

Low voltage can cause all kinds of problems with the computers or even the coils. I would try to recharge the battery and check the alternator. It sounds like your alternator is going or has gone bad. When you finally got above 1500 RPM did the voltmeter go to 13+volts? If so the alternator is good and you might have a weak battery. just in case i would pull the battery and have it checked out. If your handy i would take the alternator in at the same time.

[Chad52]

RE: Low Voltage Warning - Boat will not get up to speed....

Even at 35+ mph, the digital voltmeter showed between 11.8-12.2 volts. I never got above 13 V. I pulled the alternator last night and I'm gonna take it to get it checked today. More to follow.

[bbrech1]

RE: Low Voltage Warning - Boat will not get up to speed....

The stereo really takes a tole on alternators, especially if the engine is below 1500 rpm. Like you said that alternator didn't spin up to make the correct voltage and durring that time it sounds like you put a large load on it. You may have fried the alternator.... Yellow_Flash_Colorz:

[Chad52]

RE: Low Voltage Warning - Boat will not get up to speed....

Update: I took the alternator in for check-out/rebuild and the regulator in it was bad. Cost me $150 to repair it, which I didn't find out til it was already done. Hindsight being 20/20, I shoulda just bought the new 95 Amp version. It woulda only cost $100 more than the repair. And Trent, if your out there reading this, I don't think it had anything to do with towing the boat. It was just time for it to go.....