Battery draw

[KevinP]

My 95 YJ has an 8v draw on the battery. It goes away when I pull the big 20a fuse labeled IOD and horn circuit. Is this normal? I know there are a few things that draw like radio and computer but I thought 8v was a bit high. I have no idea what IOD is either. Any info would be much appreciated... Thanks

[Kurt]

I'm a bit confused with your description "8v of draw".
Normally battery draw (drain) is measured in amperes or milliamperes of current and not volts.
The battery puts out around 12 volts all the time unless it's badly discharged.

How are you measuring the 8v?

Yes there is always a bit of battery draw by the radio & computer. It's normally down in the milliamp range and wouldn't drain a battery very rapidly.

[ZAEDOCK]

X2 with what Kurt said.

The IOD circuit is the Ignition Off Draw. It provides power to the ECU, radio, and clock when the vehicle is off.

[KevinP]

If I disconnect the negative cable on the battery and connect a volt meter between the cable and the negative post it reads 8v. Dont know why there would be any voltage reading at all really.

[KevinP]

There is only a .0025 amp draw on the battery which should be the computer I guess. That should be pretty normal I think. Thanks for the info...

[Kurt]

The minimal drain (resistance) in series with the internal resistance of the meter creates a resistor divider network yielding the 8v you are seeing.
The mere drain of 2.5 mA (.0025 A) appears normal & wouldn't discharge a health battery for a long long time.

[KevinP]

I used a trickle charger to recharge the battery 3 times and It wouldnt hold a charge. The jeep has been sitting for a long time but I start it up now and then. When I installed the new battery I didnt have a multimeter to check it, I only had a old tester my dad had and it didnt read amps. I couldnt check the amp draw when I posted about the voltage but I still thought the voltage reading was strange. Once I got my multimeter I could test the amps and saw the .0025 amp draw. I guess I just had a bad battery. You guys always respond quickly, Thanks a lot for the advice

[Frank]

Noice trouble shooting guys ! FjR68