Tracing down parasitic draw on 98 S70.

pb49415 · Post by **pb49415** » 30 Apr 2018, 11:33

I’ve been in the process of tracing a parasitic draw. I’ve narrowed it down to the 10 amp fused circuit for the courtesy lights. I’ve been through them all and none are lighting up when they shouldn’t be. With fuse installed the draw is . 059 - .065 amps. Fuse out it’s .013 - .022 amps. With fuse in the battery’s dead in about a week and a half to two weeks. I haven’t left it sit yet with the fuse out to see if it will die. I’ve checked the glovebox and truck lights and they’re off but the draw remains. Any suggestions on a next step? I’m not really familiar with pulling the doors apart to check switches located on the locks. One thing I have noticed is that the courtesy lights above the rear doors don’t work at all. Could this be the culprit?

Post by **erikv11** » 30 Apr 2018, 12:13

I would try disconnecting the overhead light console plug by the rear view mirror, see if that changes the draw. Pop the lenses, remove the two T15 (T10?) torx screws, drop it down. I had some weird behavior of rear overhead door lights that traced to that unit.

Post by **scot850** » 30 Apr 2018, 12:52

Also check the wiring in the trunk where the harness runs up the LH trunk hinge. This is bad for breaking wires. It may have a short there.

Neil.

Post by **joejoethedogfaceboy** » 30 Apr 2018, 13:16

This post reminded me that I needed to charge the dead battery in my ‘99 S70. Did that last night and found out that the rear seat interior lights had bad switches and were stuck on. Looks like the Texas heat has caused some of the plastic in there to literally crumble

Post by **oragex** » 30 Apr 2018, 14:36

pb49415 wrote: ↑30 Apr 2018, 11:33 I’m not really familiar with pulling the doors apart to check switches located on the locks.

The switches in the door locks do go bad. Whole lock swap.
Maybe try disconnecting each door at the hinge for the night , see how much the battery drops (keep the doors closed)

Stu70 · Post by **Stu70** » 30 Apr 2018, 16:06

Remember the radio has a minimal full time draw for its memory plus any changers ,active subs or amps that are connected waiting for the remote on signal...

pb49415 · Post by **pb49415** » 30 Apr 2018, 19:45

erikv11 wrote: ↑30 Apr 2018, 12:13 I would try disconnecting the overhead light console plug by the rear view mirror, see if that changes the draw. Pop the lenses, remove the two T15 (T10?) torx screws, drop it down. I had some weird behavior of rear overhead door lights that traced to that unit.

You know I’ve thought of this too. It’s had some odd behaviors. I was wondering how to drop it down. Thanks for the information. If that’s not it I’ll try the rear door lamps above the windows. Just need to figure out how to access those. And the trunk wiring. Thanks again.

pb49415 · Post by **pb49415** » 30 Apr 2018, 19:47

Stu70 wrote: ↑30 Apr 2018, 16:06 Remember the radio has a minimal full time draw for its memory plus any changers ,active subs or amps that are connected waiting for the remote on signal...

I’ve already taken this into account. The difference between the .013 and .022 amp draw is when the radio is connected and disconnected at the harnesses. Thanks

pb49415 · Post by **pb49415** » 30 Apr 2018, 20:37

joejoethedogfaceboy wrote: ↑30 Apr 2018, 13:16 This post reminded me that I needed to charge the dead battery in my ‘99 S70. Did that last night and found out that the rear seat interior lights had bad switches and were stuck on. Looks like the Texas heat has caused some of the plastic in there to literally crumble

How do you access these rear backseat lights? Do I pop off the lenses. I’m referring to the ones located above the windows.

Post by **joejoethedogfaceboy** » 01 May 2018, 05:37

On the front side of the (tan) plastic of the handle is a little slot where you can pop it out (screwdriver or even fingernail in my case) and then slide slightly forward and out. That front side (at least on the 99) is held in with a metal clip, and the back side is a tab in a slot. As mentioned my plastic is dry and crumbly so it doesn’t stay held on the backside tab now; fair warning!