Hi,
This is an electrical question that maybe some Ford guru out there can answer.
I have a '99 F350 V10 dually. Thursday evening I went out to start it and noticed that the remote keyless entry didn't work. Well, it didn't start either. No lights, nothing. I measured the battery voltage and it was about
1 volt. Dead battery.I had driven the truck Tuesday with no problems. There was a lot of rain in the last 2 days and the truck is parked outside, usually with a cloth cover, but was not covered since Tuesday.
So, being an engineer, I brought out a 13.8vdc power supply and hooked it up to the battery terminals with the battery disconnected. I wanted to make sure there wasn't something drawing excessive current that had drained the battery, before going out and buying a new battery to replace the original OEM battery.
I was surprised to see about 4 amps of current being drawn with the doors closed, the hood light disconnected, and no key in the ignition. There were no lights on, and no accessories turned on.
No wonder the battery died with 4 amps of current being drawn when the truck is just sitting there, was my reasoning. I decided to start removing and replacing fuses and relays one by one, until the current disappeared, thus exposing the culprit.
After about an hour of fuse and relay remove/replace and connecting and disconnecting power, the current dropped to what is probably a normal level of about 160 milliamps, which I am guessing powers the clock and keyless entry and some other stuff. A little more playing around, and the current went back up to 4 amps, and after about a minute, dropped to 160 mils again.
Friday evening I installed a new battery, as my experience with 3 or 4 drained batteries in the past is once you completely drain an older battery, it never holds a charge as well as it used to. Saturday I measured the current draw on the new battery, and it is still around 160 milliamps, which I am assuming is ok.
This brings me to the questions: Anyone know if there is some sort of heater or drying unit that might be activated because of humidity, or any device or system in the truck that might draw 4 amps for a short time of maybe 1 to 10 minutes?
What is the nominal current draw at a battery voltage 12.6 VDC with nothing turned on? As mentioned, I am seeing about 160 milliamps.
As time passes I will find out if the original battery was the only problem.
Thanks for reading,
Jack