Checking a slow battery drain

[promtg]

I am trying to figure out why my batteries are draining on my boat and why the rpm guage is not working properly. First of all I have a brand new battery. I wanted to check my regulator first, so I checked the voltage on my battery fully charged 13.25 volts. I then started my motor and reved it up to approx. 1000 rpms. I then checked battery and it read 14.30 volts. My question is my regulator working properly. Next I hooked up negative leads to battery and checked voltage on the positive leads one by one. I have 4 different leads all but one measured 0.01 volts. The other one that is to my trolling motor and fish finder measured 0.10 volts. Does this mean I have a problem somewhere with the wire to trolling motor and fish finder? This is definitely not my area and any help you could give me would be greatly appreciated.

Jim

 

[Windykid]

Re: Checking a slow battery drain

The best way I track a short is to put a test light between the positive battery terminal and the positive battery cable. With the key off. If a draw is preasent the light will iluminate. Remove one fuse or circuit at a time until the light goes out. Once the light is out you have isolated the drawing circuit. Track and repair from there.

 

[Texasmark]

Re: Checking a slow battery drain

Your voltage out of your regulator at 1000 rpm's is just what you want. Sounds like it is working A-OK.

That answers one of your questions not answered by the other guys.

On Mercs, the regulator drives the tach. Usually, if the charging voltage is bad then the regulator is your problem, not your tach. But it is good, so I would be chasing the tach.

Amperage is the way I like to troubleshoot. Take your meter and put it in series with one wire of every circuit(on the amps/100's of milliamperes scale). If your power switches are off and you get any current on any circuit, there is your problem.

Mark

 

[promtg]

Re: Checking a slow battery drain

Thank you for the help. I will start checking the tach and try to isolate the battery drain.

 

[Dreddrs25]

Re: Checking a slow battery drain

Having a somewhat similar problem with my Merc. I have a 1984 115hp 2cycle, forget if its 3-4 cylinders (just bought it two weeks ago).

My tach and speedometer are coming on intermittenly, and I also have a slow drain on my battery. Two weekends in a row I've been able to run most of Saturday and then mid way through Sunday, my battery just doesn't have enough juice to turn the starter. (this past week I had an Autozone charge my battery, they said it was holding a strong charge and didn't need to be replaced)

Texasmark or anyone else: Where do I find the regulator on my engine?