Battery drain from Mercury Outboard 1991

[alukfan]

I have a constant .5 milliamp drain of power from the engine. I have measured it with an AmpMeter. This is with ALL other boat connections disconnected. Black Max 150HP 1991 S/N 0C219223. I leave battery disconnected or it drains the battery. Can anyone give me a direction? I have ordered the repair Manual just today. <br />I also go through the same 5 to 6 cranks until the motor starts. It has done this for several years even after new plugs, and carb kit. Once it starts, it is good for the whole day. Start first crank everytime!! <br />"Thanks and keep your line wet"......

 

[Silvertip]

Re: Battery drain from Mercury Outboard 1991

.5 milliamps is .0005 amps and is next to inconsequential so if that draw is draining your battery, you need a new battery. The draw is probably from leakage current in the regulator. On the other hand, are you sure you measured .5ma and didn't misinterpret the scale. As for starting, are you raising the fast idle lever and pressing in on the key to activate the choke on cold starts? Are you also pumping the primer bulb to make sure the engine has fuel available before attempting to start it.

 

[alukfan]

Re: Battery drain from Mercury Outboard 1991

Oops.....I meant to type .5 amps. Sorry I was thinking 500 millamps. Yes, my system is pump the fuel bulb, lift the lever (won't start if down),push and turn the key.

 

[Silvertip]

Re: Battery drain from Mercury Outboard 1991

If you are certain everything else is disconnected from the battery, the only thing left is a shorted diode in the charging system is allowing the current draw. Check the post on the starter solenoid that has the positive battery cable connected to it. If there is another smaller wire on that post, remove it. That's the wire that charges the battery. Now recheck current draw. If its zero, the regulator is the problem. If its still there, I'm out of ideas for the moment.

 

[alukfan]

Re: Battery drain from Mercury Outboard 1991

Well, my memory is fading these days, due to the bass fever here in the south. I hope you can forgive me. I measured it again this evening and found 3.96 on the 300mA scale. The digital Fluke has a fused input for the ampmeter at 10A and 300mA. So, this Navy Electronics dude says this is 3.96 mAmps. I traced the + lead and it went into the engine to one stud of a two studed, round black module. I removed the nut and one of the small leads, with a ring terminal, attached with the positive red lead from the battery and the 3.96 mA went away. This small fused (10A)lead goes to the rear of the engine, on a terminal block above the trim solenoids. ??? Is the black round studed module the regulator??

 

[Silvertip]

Re: Battery drain from Mercury Outboard 1991

Nope -- thats the starter solenoid. Follow the red wire you took off and it will end up at the regulator. Before you dash out and buy a regulator, make darned sure you don't have some other device still connected or turned on when you are making this measurement. If you have a digitally tuned radio, the memory and clock draws power even though the radio is turned off. Although you may have disconnected any accessories that were connected directly to the battery, you may still have something connected through the throttle/shift control box, which is fed by that red wire you disconnected. If you have a separate clock it will draw power. It still puzzles me that a 3ma draw runs down the battery. Over how a long a time is this?

 

[alukfan]

Re: Battery drain from Mercury Outboard 1991

five or six weeks......if idle two weeks if actively fishing. Always charging the starting battery. Thanks for the help. I will use my new merc manual I got in the mail. But thanks alot!<br /><br />Keep the wind at yer back , bud!

 

[GaCracker]

Re: Battery drain from Mercury Outboard 1991

Well, if it were me I'd use the Ohmeter and work backwards. You have to have a closed circuit somewhere. You can isolate the source by diconnecting stuff serially and see when you get discontinuity. IMO its easier to isolate and identify the faulty circuit with continuity.<br /><br />Also you might want to check and make sure all cables and and connectors are in good shape with no breaks or corrosion.<br /><br />Finally, a battery can self discharge under certain conditions. You might try disconnecting the battery entirely and see if it will hold a charge over the relevant time period.