Draining Battery

[BigGump]

So my truck(1990 F350 4x4 460) had been running just fine. Last friday night I parked it at 1230am, I come out in the morning at 10am and find the battery dead. I jump start it off my wifes truck and chock it up to the radio staying on when I shut the truck off. Take off drive it for 30 mins figure it would re start no problem but not the case. Later that day jump it again to get here home check altenator is charging correctly. Pulled the battery and charge it up, re install in truck starts right up. Let it sit over night dead again. Any clues on where I should start to look for something draining it. First thoughts I have are starter, or solenoid. Any ideas would be awesome as it seems that there could be many items causing it. Thanks guys.

 

[DNFXDLI]

I'd start with doing a load test on the battery...also, check the terminal voltage after fully charging it.

 

[blacksnapon]

I use a parasitic draw test adapter. Marine applications use them to disconnect batteries without actually removing them. Install it between the battery terminal and battery. Take the truck out, operating all accessories. In the garage, hook up an ammeter between the ends, then open the adapter. That should show you any draw. Then start pulling fuses to find your draw.

 

[bugeye01]

First, I agree with the batter load test, but on the truck itself, pull the ground cable off of the battery, preferrably in the dark and watch for a spark which would indicate that indeed there is a current drain at that time. Then pull all the fuses. If you have and can use a milliampmeter, then connect it at the battery cable and see if there is current flow. Probably not, and if not, then plug fuses back in one at a time until you find the leaking circuit. If the ammeter is not available, then you can still test, but be a little more patient. First night with the battery connected but no fuses, then add a fuse each night until the battery fails. One potential problem: I have had vehicles that correctly had a very, very small current drain even when everything was working right. Good luck.