Possible battery drain

[Spitfire1975]

Picked up a new (to me) ranger that may have a short draining the battery. Battery may also just be shot.

If the battery is good, and the alternator is good, what is the best way to go about finding the short that is causing the battery drain?

The truck is a 1986 2.9 Liter Ranger XL 2wd. Any help would be greatly appreciated. I do not have much electrical experience and could use a hand.

 

[kimcrwbr1]

Unhook the battery and check for continuity from the pos cable to ground the computer and radio should be the only things hooked up direct so disable them and just start pulling fuses till you locate the short then trace that system to find the fault You can start by pulling all the fuses then putting them back one at a time also while checking at the pos wire to the batt to ground for continuity. If you disconnect the alternator and the short goes away it is either the regulator or the alternator. What year is it getting a book with schematics will help you trace the wiring. You can usually find a used manual and the bone yard for cheap at least the ones around here have them.

 

[COPPERHEAD85]

Keep it simple.............have the battery checked first.
Charge it to 12.7 volts and have it load tested.

 

[Spitfire1975]

Keep it simple.............have the battery checked first.
Charge it to 12.7 volts and have it load tested.

Yep. It has been charging for 12 hours. Still hasn't finished charging. I am thinking the battery is toast, but am trying to do some "research" in case I need to take the next step.

 

[Spitfire1975]

So total time charged was 17.5 hours. Battery Charger never marked "Full Charge." Measured volts with a multimeter across the terminals. Voltage was 13. Specific Gravity tester showed same charge it had before, which was next to nothing. Cells are full.

Bad Battery?

During the charging, I unhooked the truck positive cable, but left the negative attached.

 

[88_Eddie]

take the alternator and battery to autozone or pepboys or somewhere like that and let them test it, takes less than 5 minutes

 

[COPPERHEAD85]

Take it down and have it load tested,I bet its toast.

 

[Spitfire1975]

Yeah. Will do. Seems to be holding what charge I was able to give it when not hooked up to anything.