5.0 OMC 92 Alternator issue?

[Cisco1]

Hello guys,<br /><br />Batteries keep going dead on me. However when I get the Boat started it seems to run fine. Is it possible that the alternator does not work well enough to recharge the batteries but can sustain the engine while running?<br /><br />When this rain stops I will try and test it but was wondering if anyone has come across this before. <br /><br />Thanks<br /><br />Cisco

 

[ahein]

Re: 5.0 OMC 92 Alternator issue?

Yes, I had a similar problem. Turns out that there were some aftermarket panel instruments wired directly to a hot terminal on the battery switch. Even though I shut my switch off every time, I had a slow electrical bleed that was killing my starting battery.<br />But before you go crazy trying to find a stray wire, use a multimeter to check the output at the alternator to be sure it's charging. It should be somewhere in the range of 13.7v to 14.2v. Then check the the input at the battery. Should be roughly the same range (may be slightly lower due to voltage drop in the wires).<br />If the alternator output is low (less than 13v), you need a new alternator. If the alternator output is good but the input at the battery is low, you need to check the wiring between the two. If your battery input is good, you could have a bad battery that just won't hold a charge; or you may have to start looking for that stray wire. <br />Good luck.

 

[Cisco1]

Re: 5.0 OMC 92 Alternator issue?

Great Feedback thank you. I will check as soon as this crazy rain stops I have already replaced the battery so I can take that one out. I am not sure what I am rooting for here, I guess a bad alternator 133.00 and change to replace vs searching for an errand wire.<br /><br />Cisco

 

[Blk-n-Blu]

Re: 5.0 OMC 92 Alternator issue?

Cisco, Is it possible all this crazy rain is cycling the bilge pump and draining the battery?

 

[Cisco1]

Re: 5.0 OMC 92 Alternator issue?

I suppose I should concider that. Last time I went out I had a brand new battery.(bought it that morning) Drove her WOT for about 40 minutes. Then sat and fished for about 2.5 hours with the radio on. Battery was dead. That leads me to believe that it was never getting a charge because a little radio like I have should not kill a brand new deep cycle in 2.5 hours...<br /><br />Cisco

 

[tommays]

Re: 5.0 OMC 92 Alternator issue?

the best thing you can do is buy a meter with the abilty to measure dc amps most have it now<br /><br />with the boat off connect it between the + on the battery and the cable and see how much power is being used it should be zero<br /><br />the meter will also let you test you alt output so you dont have to guess it will become your faviort tool<br /><br />tommays

 

[metwrench]

Re: 5.0 OMC 92 Alternator issue?

Tommays has a Good thought, I have something that Might even be cheaper and shows a LOW Draw. This will work with any 12Volt system that you want to Test a DRAW on. Be careful though checking Automtoive ( newer cars ) with this method as the Draw might be false to to alarms, Radios, and Computer Hot systems need a memory.<br /><br />Take a 12Volt Test Light OR any 12V Automotive Small bulb ( like a Brake light bulb or something Equilv. ) Solder 2 wires on the Bulb. With the test light or bulb ..Disconnect the Battery at either post. Put one wire from the Post and the other to the Cable end you took off. If the Light shines Bright, You have a Draw ! If the Bulb is Off..No draw. I caution you that any LITTLE Draw will make the Light go on...Specially a Low amp Bulb.<br /><br />This will tell you if you have that draw !

 

[Cisco1]

Re: 5.0 OMC 92 Alternator issue?

Very Interesting.. Going to check tonight, this might give me a good opportunity to use my new Solder Kit... Thanks guys,<br />I will let you know.<br /><br />Cisco