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bought this truck recently and fixed what needed fixing (fuel pumps). after letting it sit for a week the battery was completely dead. charged it up, alternator putting out 13.5v or so, all good. assumed that a light was left on somewhere. drove it for a couple of days and all was well. let it sit for another week and again, battery was dead. thought it might be the brand new, low end, canadian tire battery so i swapped in a known good battery from my f250. overnight it dropped from around 12.4v to around 11.1v.
having read a few things about alternators/parasitic draws i checked the alternator in the morning; not warm at all. as you may be able to see from the pic, alternator looks like a recently installed rebuilt; connector looks new.
connected meter between battery negative post and negative lead. the meter shows 2 to 3 milliamps whether it is connected or not. stumped now. since the meter is not registering a draw i see no reason to go through the procedure of removing fuses one by one. this is my first time attempting to diagnose a parasitic draw. need help. thanks.
the alternator is definitely putting out enough voltage to charge the battery; drive it daily and there are no issues, leave the truck sit for a week and the battery voltage drops to around 4 volts.
If your meter is always reading 2-3 milli-amps I suspect a blown meter fuse.
Typical parasitic draw is ~50 mA on these trucks.
Your meter and leads look correct to me assuming one lead is on the battery negative post and the other on the negative battery cable. Effectively putting the meter in series.
When you go from the neg post to the battery you should have the meter set on volts DC, without the truck running.
I use meters as well but for this stuff a 12-volt bulb and socket with some long leads is a little easier to manage. Hook to the neg post as you did and then touch around with the other end to see if light glows when you find power that should not be there. To me, it is easier to see a bulb than try to read the face of the meter. Just my two cents.
If your meter is always reading 2-3 milli-amps I suspect a blown meter fuse.
Typical parasitic draw is ~50 mA on these trucks.
Your meter and leads look correct to me assuming one lead is on the battery negative post and the other on the negative battery cable. Effectively putting the meter in series.
3g alternator for sure.
thanks ... i thought that there should be more milliamps showing than that. will check it out. also glad to know the 3g conversion has already been done.
When you go from the neg post to the battery you should have the meter set on volts DC, without the truck running.
I use meters as well but for this stuff a 12-volt bulb and socket with some long leads is a little easier to manage. Hook to the neg post as you did and then touch around with the other end to see if light glows when you find power that should not be there. To me, it is easier to see a bulb than try to read the face of the meter. Just my two cents.
thank you. i did know enough to run that test light check on the alternator but didn't know enough to poke around in other places with that same method. this gives me more troubleshooting ability.
