Dead Battery! Need electrical advice...

[Bellime]

Taking ...FWB's advice a bit farther.

1. Get a cheap multi-meter from Harbor Freight ($8).

2. With a charged battery and everything off... at night check the voltage across the battery and write it down.

3. Check the voltage in the morning... has it changed. If it has, then you are getting a draw-down somewhere. If the draw-down is say 0.3 volts... then a certain amount of amps are being used, and once the battery hits about 10-11 volts it is essentially dead. The volts draw-down though depends on a bunch of factors (like when the computer is on, sleeping, or in a deep sleep). What does "deep sleep" even mean? The fact of the matter is... the computer still has to draw enough power to monitor sensors so it knows when to wake up.

Checking Winch:
4. Set the multi-meter to the "amps" setting.

5. Disconnect the winch, and put the leads from the multi-meter inline with the winch-cable and the battery. See if there is a reading. If there is... this is the problem. If the draw is (for example) 0.25 amps... then the battery will probably be drained completely in say 200-400 hours).

Go to Harbor Freight or someplace and get a relay that can be toggled on/off for powering the winch. It will have to have enough amps to withstand the use of the winch. Hook it up so the relay on/off function is powered by one of the Aux switches.

6. In older cars you could hookup the multi-meter as in #5 for the entire car, but since the Bronco is so computer activated/driven beast when you hook up power... I have no idea how much normal power draw is once it goes to sleep. I believe "Mid" and "High" packages draw more power than the Base package.

Fun fact -- I had a 2001 Mustang. If I left it at an airport (or anywhere) for a couple of weeks then it would be too dead to start. It had no add-on options. That's just the way it was. I had to disconnect the battery (with a manual battery disconnect after this happened a couple of times).

This would be the easiest way to solve your problem (if its not the winch) (i.e. a manual battery disconnect), but I'd talk to the Ford Service guys and ask what happens when the computer is completely disconnected from power for an extended period of time.

O.

I like your advice to add a battery disconnect switch to the winch. By default this is great protection.

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[Texasliam]

Yes... the Harbor Freight ones are pretty OK. Not a a Fluke, but pretty much the same readings for the simple stuff (volts, ohms, etc).

The Bronco start up sequence draws more amps than that cheap multimeter can measure. More than 5 amps fir sure. And It will pop the meter fuse. So get one that can handle higher amperage.

 

[Owl]

You won't be able to measure amps at startup. I don't know what that would accomplish by doing that. You need to be able to see what the amp draw-down is when your Bronco is in a quiet mode... with all accessories (to your knowledge) off.

At least that is my thinking.

Just an FYI... at startup you will draw 200-500 amps... or more.

 

[JohnnyBronco]

You won't be able to measure amps at startup. I don't know what that would accomplish by doing that. You need to be able to see what the amp draw-down is when your Bronco is in a quiet mode... with all accessories (to your knowledge) off.

At least that is my thinking.

Just an FYI... at startup you will draw 200-500 amps... or more.

Draw at startup will indicate starter problems and not much more. You can pull the starter and have it tested at many auto parts stores. Same with alternators.

But with several other threads indicating continual internal draw from winches it makes sense to completely idolatr the winch with a Cutof switch or a plug.

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