voltage leakage

[driver27]

I have a 2004 F150 and have what I think is some voltage leakage, looking for ideas.

If I check the hot and ground leads from the motor, I have some voltage draw. With nothing but these leads hooked to the battery, There is some draw when I disconnect the ground cable and check draw between the ground cable and the neg battery post. It is enough that it draws my battery down in pretty quick order. Looking for ideas of what to test on the motor to try and find the source. Is it possible that the problem could be in the ignition switch? I have the leads which connect the power to all accessories disconnected when I do this test, so I do not believe it is a leaking radio, lights, GPS, etc.

I am not electrical genius, so any ideas and things to test would be greatly appreciated.

[jazzman44]

measure the voltage while the engine is idling. It should be above 13 odd volts. Switch the engine off, and measure the voltage. It will fall to around 12,8 Volts. If it falls rapidly to around 12 or less, get a new battery. While the engine is off, measure the current drawn from the battery, it should be less than 100mA, with the ignition in the off position. If it is more than 100mA, find the culprit that is draining the battery.

[driver27]

It is a bit more than 100mA, but not a whole lot. Charging voltage is good, when running and this is a new battery. The old one was so discharged it would not take a charge.

I have been keeping the battery cables unhooked to prevent killing this new battery.

It runs fine, cranks fine and does not have any weird issues.

I was just wondering if anyone had any ideas on where to look specifically. I assume the digital gauges also get power from these main battery cables as they are not fused into the house circuit anywhere I could find.

Thanks

[jazzman44]

i have nothing connected to my main battery that is used for starting and starting only.
my clocks and everything else goes through the house circuit which i can isolate when ive finished if i loose the power to the house battery i can always start the engine i don't chance anything that could drain the main battery

[driver27]

Yes, I am set up that way too, the only thing on the starting battery is the 2 main cables (+ and -) from the engine. I believe those feed the ignition switch and the digital gauges as well however. Everything else in the boat goes to a house battery.