truck electric leak

Karl,

Pull *ALL* the fuses - then replace one at a time for the test. Then remove that one and try another.

Then disconnect the alternator. Could be a shorted diode.

Everything isn't on a fuse...

Both the alternator and the starter are on a fusible link that is tied into the wiring... If pulling all the fuses doesn't find it, pull the large wires off the starter and alternator...

Use the ammeter function between the + post of your battery and the wires that normally connect to it.

You will see the amount of current that is draining the battery. As others have posted, remove the connections to fusable links as well as to the starter to determine where the current is going.

--Winston

That would take 43 days to drain a decent battery using my conservative numbers.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Agreed. Use an amp meter, not an ohm meter to isolate the issue. Start on the largest setting first, then work your way down if you can. I had to do this on a camper recently.

Wayne D.

How much is it drawing? Put an ammeter in the GROUND lead; set it to 10 amps, and go downscale from there. If it's an amp or more, put a 1034 or similar taillamp in series. Then you can disconnect things and observe success.

Others have suggested the alternator, which I second. Pull both the output wire and the field connections.

Also, do you have one or 2 fuseboxes on your truck?

Karl Townsend wrote: (clip) So, today I put the ohm meter between the + post and ground. Got 180 ohm. (clip) ^^^^^^^^^^^^^^^^^^^^^ Are you reading from the positive battery post to chassis ground with the ohm meter? That's not a meaningful reading, since you are putting the 12 volts in series with whatever your ohm meter has internally. Actually, if this is the connection you are using, you are making some kind of across the battery itself, and not looking at the circuits that could be draining the battery.

Do what others have suggested: The handiest way to measure is to disconnect the ground cable and insert a current range of your VOM. You should see any current being supplied by the battery. Then disconnect the positive battery cable and the current should drop to zero. That will tell you that you are on the right track. Then pull fuses or disconnect wires until it drops to zero again. That will be the *aha* moment.

On my 91 Ranger the leak was a stuck relay under the air cleaner box that kept the engine control computer ON all the time.

Applying voltage to a digital meter on the Ohms scale gives a bad reading, with an analog meter the smoke makes the scale hard to read. I put a low value power resistor in the Ground lead and a voltmeter across it to check the current. It doesn't matter too much that the current reading isn't accurate and if I accidently turn on a power load the meter will survive.

The light bulb in series with the ammeter is a good idea too. If they still sell them, a replacement tail light socket has two separate wires you can attach alligator clips to. That was the only test equipment I carried on my motorcycle, for checking bulbs and fuses and setting ignition timing.

Jim Wilkins

I narrowed the problem down to my alternator. Drain of .2 amp.

So, I tried to remove the alternator a got into A REAL MESS. the bottom bolt is rusted on. Put a 3/8 x 9/16 socket on it and couldn't budge it. Put a

1/2x9/16 socket on it with my S-K Wayne ratchet and couldn't budge it. Bounced on it, the wrench came loose along with a bunch of knuckle blood. Put a cheater on a 9/16 impact 6 point socket - the socket spit in two parts - never seen that before. Took the radiator out and put my impact wrench on it, still no joy. I said something like mother f%^& c*ck %^*&( and called it a day.

Karl

Karl, as the liberals would say, with feeling - "I feel your pain" - and what makes you feel even worse is having set yourself up to do it - there is ALWAYS a strategically placed bracket whose only function is to inflict injury.....

Well, so much for humour - is this the same truck you were having trouble with a while ago (last winter?) - it was giving you a hard time in the battery charging area, then it sort of spontaneously fixed itself for a while. As others have said, its probably the diodes in the alternator (or, possibly, the voltage regulator)- while your in there, particularly if its got a lot of miles on it, replace the brushes on the slip rings, and the front and rear bearings.If your not comfortable with doing the electrics, your local auto-electrician (if there still is one) should be able to test/diagnose it for you.

I have pulled a few apart in recent months, want to make a wind generator out of one - interesting devices, particularly in how the get the rotor onto the driveshaft......the 9 inch angle grinder DOES have many uses....

Did you soak it in Liquid Wrench for the night?

You got a good memory. Also, the volt drain must not be a constant, it drained a new battery in a couple days. I'd check and couldn't get any ohm reading ( or current - same thing)

Maybe I'm too rich, I just trade in alternators. Too much trouble to rebuild wrong and have to do it again.

To the other post - deep creep once per hour till bedtime. if that don't work, I'll give the alternator the rose bud - but I got to remove a whole pile of rubber hoses before I do that.

If that don't work - I may be screwed glued and tattooed. Don't see how else to remove it. Probably pull the engine.

Karl

Kroil hammer tap... Kroil hammer tap... Kroil

On senior son's 68 Firebird, it was the horn relay. Gerry :-)} London, Canada

No.... not the same.. Use an ammeter, or the lamp trick. The ohmmeter can lie to you, and send you down dead ends.

Your concern is current leaks, look for that...

Kroil is so good that sometimes just showing the offending bolt the Kroil can is enough to scare it into submission...

It probably isn't, but check that there is not a nut on the bolt hiding behind the bracket. It is fairly likely that the bolt is siezed in the frame of the alternator and will require drastic measures. If accessible, application of a heavy hammer as if to drive the bolt in lengthwise often helps. Just remember to sacrifice the correct parts first. ;>)

Don Young

Theory that is.

In these days dropping below a certain level kills the CPU card.

I've seen small batteries that can 'fill' a flat one in seconds - floating it long enough for the engine to have a brain - then it generates.

I couldn't leave my 80's New Yorker when it first came out - The battery would not last 2 days. I could not fly out of town and leave it.

The clock and internal computer and the 12V CMOS processor - the regulator for the processor blocked all until above a level.

Mart> "Karl Townsend" wrote: