Killing the battery

Ok guy's. My uncle has a 86 toyota pickup that keeps killing the battery and I do mean killing the battery. We have replaced the Alternator 3 time and the battery 4 time. When everything is done it runs good and charging at around 14v. You can drive all day with no problems and maybe a day or two then leave it set over night then the battery is dead and won't take a charge. Replace the battery and it will start and run good. Some time it will start every day for a week or two then go and start it for the first time in the morning and nothing no power at all. Like I said we replaced the alternator 3 times. And need to replace it again because this time we let the smoke out of it . I've checked for a draw on the battery and nothing. Everything i checked says that it all good so I don't know what it going on. So need help on what to checke and see what could be killing the battery. Any info would be appreciated thanks.
Andy
P.s it has the 22r engine

 

I have a draw on my 86 that I can't figure out either. I ended up wiring in a battery disconnect into the cab. It's one of the ones that takes a special key so it also works as an anti theft measure. I just moved any wiring that was direct to the battery to the uphill side of the disconnect. Prolly not the best fix but until I figure it out I don't have to worry about my battery going dead all the time.

 

There's 2 white wires that run from the alternator, the large post on the alternator, and a small one in the plug to the alternator, to the battery. The smaller, white wire in the plug of the the alternator, to the 'FAR SIDE" of 80A Fusible Link, the side opposite the 80A FL from the battery, in the fuse box in the engine compartment. Right behind the battery. From there, it's connected to the FL that is connected directly to the Battery + (positive) terminal. That smaller wire is the charge sensing wire from the battery, telling the alternator's circuitry how much voltage to apply to the battery through the large white wire, which is connected directly to the battery + terminal. Have you checked both of those? Disconnect the battery, both terminals for safety, and the alternator, the plug and the large terminal, and ohm from the battery + terminal to the terminal that goes onto the large post on the alternator. It should be less than 1 ohm.
Remember to disconnect both terminals from the battery. It takes very little to smoke-check a multimeter in ohms mode.
Also, ohm from the battery + terminal to ground. With both ends, the battery+ terminal, AND the alternator large terminal and plug, isolated from ground, and both the battery and alternator, it SHOULD read infinity ohms. If either reading is bad, you've found the problem.
Now you just have to start following wire down to the short. Sounds like a wire has rubbed through some place, and is shorting to ground.
If the alternator isn't charging the battery properly, IE: one of the FL;s is broken/burnt, then when the truck is running, it's running off the battery. It doesn't take long running like that to drain the battery, and quite probably short a cell in it, making the battery bad permanently. It will never again take a charge, and any charge it has remaining will quickly drain off.

Speaking of ground(s), check the 4 main ground points in the engine compartment. Battery to body, battery to engine, head to body, and alternator to engine. If you aren't sure where they are, there's a thread in the Stickies section that describes, with pictures, just exactly where they are. There are also two inside the cab, one behind the kick panels on either side. Make sure the wires are good, no breaks, or cracks in the insulation, and the connections at the ends are clean and shiney, no corrosion or dirt, both the terminals and the metal they are connected to. Don't be afraid to give each wire a small tug at each end to ensure the crimp of the terminal is good. It can look good, but not be making a good connection all the time. As the truck moves around, they can flex, so simulate that.
Corrosion can develop under the connectors, especially since they are a different metal than what they're connected to. This can cause what's known as Differential Metal corrosion. The same happens in the cooling system, especially between the head (aluminum) and block (iron). That's why the antifreeze you should use is the red stuff from Toyota. It's designed to try and reduce the corrosion as much as is possible.

Another way you can check to see if there is a constant drain from the battery is to disconnect the positive from the battery. Hook the multimeter positive lead to the battery positive post, and the negative lead to the wiring that was connected to the positive terminal. Make sure the multimeter is in AMPS mode! The highest scale it has. You can always drop the scale down, but if it's set too low, and there's too much current flow, it will blow the fuse inside the multimeter.
Anywho, there should be absolutely zero, or very very low, current flow out of the battery when everything is shut off. Key off, no radios, nothing. There may well be a small amount of current flow, as I believe the ECU has a "keep-alive" draw, and many radios do as well, but it should be very low. Less than 500mA, IIRC.
If you have too high a current draw, it may be draining the battery. Start pulling fuses to find the circuit with the high draw. Once you've isolated the bad circuit, you can start tracing down it until you find just exactly what, and where, the draw is.

Hope this is some small help...
Pat☺