Electrical problems
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Turn everything off. Doors closed, all aftermarket electronics disabled. Disconnect the + lead of the battery and look into the truck with an ohmmeter with one lead to ground and one lead to the disconnected lead of the battery. You will read ohms, R.
R=I/12.6.
In other words, 125 ohms will produce a tenth amp of parasitic drain. And so on. You can do the math.
Pop the connection to the voltage regulator and redo the test. The solid state regulator may be causing the problem.
Continue removing fuses until you find the drain.
Your starter is not the problem.
Xstrange will wander into the room soon. He is a very smart guy.
Semper Fi
Ford Trucks for Ford Truck Enthusiasts
Sorry I'm late; I've been busy running the business......
All of the above is good....check for a parasitic drain. Think of it like a leaky hose. I normally use a small digital multimeter on the Amps setting. With everything shut off, disconnect the negative cable and put the meter probes on the cable and on the battery post. You shouldn't be seeing any current flow at all. These old trucks don't have no stinkin' computers! If you find some leakage, it's most likely some "aftermarket" wiring, like an audio or alarm system installation. As mentioned above, you track the leak down by pulling one fuse at a time while checking the meter. That'll tell you which branch of the system the leakage is in.
However, first things first......Your comment about using reconditioned batteries raised a warning flag. There are a whole lot of junk batteries out there these days, which will slowly drain down by themselves, just because they feel like it. On one of my cars, I recently went through 3 new Pep Boys batteries (under warranty) before I got one that didn't slowly leak down by itself.
So, check the battery itself first. Pull off the negative cable and measure the voltage across the battery. Let it sit for two days with the cable off and check it again. If the voltage drops by itself with nothing connected, then the battery itself has a small internal electrical leak. A reconditioned battery is even more likely to have that leak than a new one, and it won't necessarily show up on their load test.
Sorry I'm late; I've been busy running the business......
All of the above is good....check for a parasitic drain. Think of it like a leaky hose. I normally use a small digital multimeter on the Amps setting. With everything shut off, disconnect the negative cable and put the meter probes on the cable and on the battery post. You shouldn't be seeing any current flow at all. These old trucks don't have no stinkin' computers! If you find some leakage, it's most likely some "aftermarket" wiring, like an audio or alarm system installation. As mentioned above, you track the leak down by pulling one fuse at a time while checking the meter. That'll tell you which branch of the system the leakage is in.
However, first things first......Your comment about using reconditioned batteries raised a warning flag. There are a whole lot of junk batteries out there these days, which will slowly drain down by themselves, just because they feel like it. On one of my cars, I recently went through 3 new Pep Boys batteries (under warranty) before I got one that didn't slowly leak down by itself.
So, check the battery itself first. Pull off the negative cable and measure the voltage across the battery. Let it sit for two days with the cable off and check it again. If the voltage drops by itself with nothing connected, then the battery itself has a small internal electrical leak. A reconditioned battery is even more likely to have that leak than a new one, and it won't necessarily show up on their load test.
I should go take a look at the hi-beam switch on my '67 just as a precaution.
Before you check anything else, read and note the B+ voltage after you remove both cables from the battery. Now allow a few days for the battery to bleed down and re-check. A good battery will loose no voltage and read the same before and after.
My bet is that 'reconditioned' battery is the culprit. Knowing what it takes to build a battery, I see no proper way to 'recondition' one. I suppose you could drain the battery, wash the cells with water to remove the sulfate sediment, add new acid and charge it again. In all honesty, this is an old battery that's been give the "Snake Oil" treatment.
At any rate, you will probably want a (brand) new battery anyway.
Let us know what you find.
Ray
About the reconditioned batteries:
Most people never notice a battery that has a small leak down. Most "normal" car owners have a single car that they drive at least once a day, and usually several times per day. So they never notice a problem.
And then there are wackos like me. I own two cars and two trucks, all of them 20-44 years old. And I drive about 3000 miles per year total. I have a nice compact life with no daily commute. I try to rotate the use of my vehicles when I need to run errands, but sometimes one may not get its exercise for a week or two. That's why I know about slow leaks in wiring and batteries. One of my cars has a slow leak in some ratty "aftermarket" wiring under the dash and it will be dead in three days. On that one, I automatically disconnect the battery cable every time I park it at the shop. I haven't gotten around to crawling under the dash and fixing it yet.
I've had my '67 F100 for 14 months and haven't had to charge it or jump it yet.






