Low battery / constant drain

[Restoredrust]

hey, so here's the deal, my 1986 Scottsdale keeps having low battery when I go to start it up, I'll charge it and it will be good for an hour or two but then I'll need to jump it or charge the battery again, if I jump the truck it runs great no problems starting what so ever, I haven't tested the battery yet to see if it's good but it's a relatively new battery, I bought it 2-3 months ago. I was wondering if anyone knows what wires should be hot and what wires shouldn't be hot when the truck is off, it's really frustrating haha thank you!

 

[Honky Kong jr]

You can do an amp draw test but you'd need a clamp on amp tester. You can also disconnect the battery positive cable put your meter between the battery and the disconnected cable start pulling fuses. If no change put it back and move on to the next fuse. If you pull a fuse and it goes to zero or drops a bunch that's your draw.

 

[Daveo91Burb]

Be careful if you use a regular, consumer grade meter (not the clamp on type) and put it in line with the battery - sounds like you have a significant current draw that could easily blow your meter or its fuses (don't ask me how I know this....the fuses I blew were hard to find)

 

[Cuba]

X2 what Dave said^^

If you don't have an Amp clamp, use an incandescent test light.

Disconnect the negative cable on the battery. Use the test light inline to connect the cable to the battery. At this point, the test light should be glowing bright... this is the draw... You are "seeing" it versing reading the amps draw. Next try pulling fuses, one at a time to see which of the fuses pulled reduces the brightness of the test light bulb. This will be the circuit to focus on... or at least one of. When you have found the main culprit, the test light will still be lit but very very dimly.

If you've gone through all the fuses and none affect the brightness of the test light, this means it's one of the "always Hot" circuits... such as starter cable, Alternator cable, Ignition switch cable...

Post back after if you need more help. Try to keep the battery charged up with the maintenance charger. If the battery runs too low for too long, this will kill it prematurely. You can use the maintainer on the battery while using the test light draw finding.

Just realized Honky posted similar using the meter... I find it easier with the test light... not have to read the meter.
*sorry Honky

 

[Honky Kong jr]

Sorry put your meter on 20amp scale. Not milliamperes. @Cuba yes the test light is easier I also have made noid lights to put into fuse boxes to find shorts.