Battery Draining overnight (1 Viewer)

[Texas Navy]

Hey all, I need some guidance from those smarter than me. Truck is a 1997, and I put a new Optima Red Top in it 4 months ago. As of 3 months ago, if the truck sits for more than. A few days, the battery is completely dead. It has gotten to the point where if the truck sits for 30 min it needs a jump. I know part of that is related to the now-damaged battery, but I don't just want to thump a new battery in and repeat all this.

I don't know where to start to find whatever vampirism load I have. The lights aren't on, the radio shuts off when the truck does. No aftermarket lights or anything, and I don't see anything obviously aftermarket and electrical outside of a double-DIN radio. Where would you start?

I've only owned the truck since May, if it matters.

Thanks all!

 

[gummycarbs]

No alarm?

 

[Texas Navy]

No alarm?

Has an alarm that goes off when I put juice back to it. I generally leave it bypassed anymore, with the red light on the dash to the left of the wheel. I think it's stock?

 

[gummycarbs]

I generally leave it bypassed anymo

How?

 

[ppc]

Fully charge the battery then disconnect it completely and measure the voltage over time. It it goes dead/low you know its a bad battery. If not then its time to measure current draw circuit by circuit until you find one that has excessive amperage.

 

[gnob]

likely the red top.
check the parasitic draw.

 

[Texas Navy]

How?

Has a toggle switch in the wheel well on the left side. Flip it forward and it is bypassed.

 

[Texas Navy]

Fully charge the battery then disconnect it completely and measure the voltage over time. It it goes dead/low you know its a bad battery. If not then its time to measure current draw circuit by circuit until you find one that has excessive amperage.

Ok, thanks. I have a scanguage as well and I've been using it recently with the truck running. I'm still getting 14.5ish volts with the engine on, so I think the alternator is still ok...?

 

[clx16]

Things plugged in to OBDII can have some draw but i doubt your scanguage has that much pull. You can find a good ground and then take voltage on each side of each fuse and see if you see a difference. its sort of like using the fuse as a shunt (for amp meter) and if one side of the fuse has lower voltage than the other then you have some draw on the circuit.

 

[Texas Navy]

Things plugged in to OBDII can have some draw but i doubt your scanguage has that much pull. You can find a good ground and then take voltage on each side of each fuse and see if you see a difference. its sort of like using the fuse as a shunt (for amp meter) and if one side of the fuse has lower voltage than the other then you have some draw on the circuit.

Awesome, thanks. I'll give that a go as well.

 

[gummycarbs]

Has a toggle switch in the wheel well on the left side. Flip it forward and it is bypassed.

I don't think that switch is doing what you think it's doing. I believe it's a valet mode switch. The alarm brain is still entirely connected and drawing power.

It's probably your alarm. It almost always is. But you can use a multimeter in ammeter mode to narrow down the circuit that's drawing power.

 

[1973Guppie]

My bets on a bad red top Optima. They are not the batteries they once were. Run it and put a meter on the batt posts to read voltage. Should be 14+. I would get the battery tested or charge it up and monitor how much it drops. I use costco rv deep cycles in all my trucks. They work great and can sit for awhile. When they die I usually get some type of credit when I trade em in. Good luck.

 

[BILT4ME]

My bet's on a bad RS3000 alarm system. Rip it out by the roots.