2005 mercury 50 ELPTO

StriperChris22

Recruit
Joined
Aug 25, 2005
Messages
5
My 2005 Merc. 50 ELPTO, the other day the tach quit workin and it seems that it isn't charging the battery like it should, usually when you are going down the lake wide open the volt gauge shows 12.5-13V. it only showed 11.9 last trip, what gives? i got it at Bass Pro. It's under warranty so they are taking care of it. I'm just wondering how these things work. Being a gear head and a diesel tech. I like to know how my stuff works. I can build a diesel engine in a truck so I hope these thing s are too intimidating. Thanks!!!<br /><br />Chris
 

Kiekhaeferscurse

Petty Officer 2nd Class
Joined
Nov 25, 2004
Messages
173
Re: 2005 mercury 50 ELPTO

Tachs, are drivin buy the regulator/rectifier,like the voltage guage is telling you it isnt charging causing it isnt rectifing anymore.. R&R
 

Wellcraft 89

Petty Officer 2nd Class
Joined
Aug 5, 2002
Messages
158
Re: 2005 mercury 50 ELPTO

I would recomend that you get a manual on your engine.get one from mercury <br />Rich
 

StriperChris22

Recruit
Joined
Aug 25, 2005
Messages
5
Re: 2005 mercury 50 ELPTO

Problem was the voltage regulator and the wiring harness for that was burnt up. Tech. says he has never seen that before that bad. Brand new boat, 1 year old, what could be the problem, just a bad/shorted regulator, or maybe a shorted or reversed polarity battery. Should I get a new charging battery to be on the safe side. He showed me the wiring harness and it was like it was lit with a torch. Anybody else ever heard of this??
 

andy6374

Lieutenant Commander
Joined
Aug 4, 2005
Messages
1,617
Re: 2005 mercury 50 ELPTO

What I always thought was confusing about the whole setup is...<br />- You have (or at least on my engine, 9 amp stator) the two yellow stator wires coming to the two stator terminals on the rectifier. This AC voltage/current gets rectified and is sent to the third terminal (+ terminal) which you then connect to your starting solenoid which in turn is connected to your battery and hence you get charge. But....<br /><br />The gray wire, which supplies power to the tach via the wiring harness, is connected at one of the stator terminals on the rectifier and hence you are sending an AC voltage throught the wiring harness to the tach. You then have a jumper wire from the tach to the voltage gauge. So here's the question:<br /><br />How can the voltage gauge tell you what the charging voltage (DC) is when it is getting an AC signal?<br /><br />-thanks<br />andy
 

andy6374

Lieutenant Commander
Joined
Aug 4, 2005
Messages
1,617
Re: 2005 mercury 50 ELPTO

What I always thought was confusing about the whole setup is...<br />- You have (or at least on my engine, 9 amp stator) the two yellow stator wires coming to the two stator terminals on the rectifier. This AC voltage/current gets rectified and is sent to the third terminal (+ terminal) which you then connect to your starting solenoid which in turn is connected to your battery and hence you get charge. But....<br /><br />The gray wire, which supplies power to the tach via the wiring harness, is connected at one of the stator terminals on the rectifier and hence you are sending an AC voltage throught the wiring harness to the tach. You then have a jumper wire from the tach to the voltage gauge. So here's the question:<br /><br />How can the voltage gauge tell you what the charging voltage (DC) is when it is getting an AC signal?<br /><br />-thanks<br />andy
 

Stew130

Recruit
Joined
Jul 23, 2008
Messages
1
Re: 2005 mercury 50 ELPTO

just had this happen on mine. it's a 2000 50elpto. it has always acted weird where sometimes the tach would jump around or just not work, i could never track it down. well it finally gave up and when i dug into it i found the two yellow wires coming from the stator had melted together at the bullet connectors and was jumping power between them. i had to use a knife to separate the connectors from each other. when i did a static check on the voltage regulator it was toast. not sure why the wires fried like that, engine heat or electrical current, but i am going to fix the connectors then get a new regulator and hopefully that will fix it. i have pics of the wires if anyones wants them, just shoot me a message with contact stuff.
 
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