1993 90 hp EVINRUDE V4 CHARGING PROBLEM BATTERY DRAINS !!

okditch

Cadet
Joined
Sep 6, 2009
Messages
23
motor will start and run with enough voltage...12.2+v,but seems not to be charging (fish finder voltmeter shows only batt. voltage when it used to show 13.5+-v).LOAD TESTED BATTERY OK. I took off neg batt. lead to motor tested (with key off) amps on black multi lead to the cable and red to battery terminal(NEG) meter read a BACKWARDS draw of 40mA (i think ).DOES THIS MEAN MAYBE THE RECTIFIER IS DRAWING BACKWARDS???ALSO THIS IS AN ALL ALUMINUM BOAT IF THAT MATTERS.I ALSO GET A REVERSE DRAW FROM THE CABLE(BLACK)TO THE HULL(WITH NO NEG BATT CONNECTION) CAN ANY ONE DECIPHER THESE RESULTS?BOAT WAS TRAILERED DURING TEST, AND BATTERY WILL DRAIN AFTER SEVERAL DAYS.I BOUGHT THE RECTIFIER/REG, SHOULD I ASSUME THATS THE PROBLEM AND SWAP IT OUT? THANKS FOR YOUR CONSIDERATION!:D:D:D:confused:
 
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ezeke

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Sep 19, 2003
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12,532
Re: 1993 90 hp EVINRUDE V4 CHARGING PROBLEM BATTERY DRAINS !!

Each side of the rectifier converts AC voltage to DC voltage as it come off your alternator. It does this by using diodes that allow voltage to flow in only one direction. Any voltage that reaches the diodes going in the wrong direction will instantly destroy the diodes.

You can destroy the diodes by charging the battery with the battery connected, by disconnecting the battery while the engine is running, By having loose cables and a half dozen other ways, like running tests with the battery connected and having a bad ignition switch.

Anyway, check the rectifier as Mr. Reeves describes in the Engine FAQ forum unless you have a peak reading voltmeter.

http://cdielectronics.com/downloads...ues, Regulator-Rectifiers and Tachometers.pdf

BTW, if the battery is slowly discharging, you have a leak somewhere; you can usually locate the problem with an ohmmeter, but you will have to check your system wire by wire. Normally, the wiring system is not grounded to the hull on an aluminum boat except indirectly, but most owners have a switch to disconnect everything on the battery except for the bilge pump when the boat is not in use.
 

okditch

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Sep 6, 2009
Messages
23
Re: 1993 90 hp EVINRUDE V4 CHARGING PROBLEM BATTERY DRAINS !!

actually, I did charge the batt while still connected..a few times didnt think that was bad ..oops ! What about that backwards current? what could cause that. I am grounded to the hull with the accessory breaker cluster how do i avoid grounding to the hull? even the throttle controls are grounded to the box ,and the box is connected with bolts to the metal hull right?My motor is isolated by a wood transom should my breaker box be grounded to the motor then? would i have to isolate every possible leak and is that possible?
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: 1993 90 hp EVINRUDE V4 CHARGING PROBLEM BATTERY DRAINS !!

You can't avoid grounding to the hull because your motor is bolted to the hull, but you should avoid running current through the hull by having both positive and negative blocks wired to the battery.
 

Mr Bob

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Mar 3, 2008
Messages
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Re: 1993 90 hp EVINRUDE V4 CHARGING PROBLEM BATTERY DRAINS !!

I'm having a charging problem with my 1990 90hp
The tach is not working, I was wondering why the question 'does the tach work' was asked??

I posted this question on the wrong thread and can't seem to find where to delete it:confused:
 
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wilde1j

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Apr 15, 2002
Messages
5,964
Re: 1993 90 hp EVINRUDE V4 CHARGING PROBLEM BATTERY DRAINS !!

If the tach is not working, good chance the R/R is bad.
 
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