Parasitic draw, maybe?

hear

Can't type
Original poster
Lifetime Supporting Member
Joined
Oct 18, 2020
Messages
4,145
Location
Prosper, TX
My 97 has had the battery unexpectedly die on me after a few extended stints of no driving. I noticed that I've sometimes got a front marker (just the driver's side) that will stay lit sometimes, and then other times won't be lit. I did recently change out the light switch unit because the headlights would occasionally just go out, but wiggling the switch would get them back on. So I kinda suspect my parasitic draw is related to that. But I also changed out the radio so it could be related to that too.

That said, do we have a good technique for isolating the circuit that has a current draw with the key off?
 
My 97 has had the battery unexpectedly die on me after a few extended stints of no driving. I noticed that I've sometimes got a front marker (just the driver's side) that will stay lit sometimes, and then other times won't be lit. I did recently change out the light switch unit because the headlights would occasionally just go out, but wiggling the switch would get them back on. So I kinda suspect my parasitic draw is related to that. But I also changed out the radio so it could be related to that too.

That said, do we have a good technique for isolating the circuit that has a current draw with the key off?

I've always been told to test for voltage in parallel. This is more of a modern thing, but some cars (idk about the TJ, the electrical system was the one thing that didn't fuck up on me) will actually "wake up" their modules and start sending 5,12, etc. volts to all the circuits when fuses are pulled or doors are opened. I'd be checking the radio (the switched fuse) fuse for any voltage when it's all powered down. New radio could def do it.

First, make sure you have a draw. Run an ammeter in series between the - post and - cable.
 
Last edited:
  • Like
Reactions: hear