Pasatitic power loss via Dome circuit

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WomblingFree

10 Year
Joined
Jun 13, 2012
Threads
9
Messages
45
Location
Sydney, Australia
Hi
My truck is chewing up some 150mA (should be 30mA) when it's parked, locked and everything turned off.
Occasionally, after an hour or so the current may drop back to 30mA.

Have traced it to the Dome Light circuit which also runs the intrusion alarm or body computer.
If I open/close a door and it adds another 100mA even with no lights enabled. Close door and back to 150mA.
I can kill the wiring to everything but the intrusion alarm or body computer so its looking like the problem is in this area.

Anyone have any experience with these?
Apart from the high consumption, everything works perfectly.
 
dfrelich said:
Have you tried taking out the fuse for dome. See if there's any other draw that's higher than 30?
Click to expand...

Yes. Thats how I know it is the Dome circuit that is at fault.

As I said, it looks like the excess current is being used by the body management computer or the intruder alarm computer. At least thats what my wiring diagrams say once you strip out the dome lighting circuits.
I don't know where these two items are located but hopefully someone has had experience dealing with them.

Its interesting that Google turns up quite a few instances of 100 series dome circuit power around 150mA but I have yet to find anyone who has solved the problem of where it goes.
 
any update? Interested in the outcome as I was replacing dome bulbs tonight and now no interior lights work and the alarm and FOB don't work.

Thanks
 
WomblingFree said:
Hi
My truck is chewing up some 150mA (should be 30mA) when it's parked, locked and everything turned off.
Occasionally, after an hour or so the current may drop back to 30mA.

Have traced it to the Dome Light circuit which also runs the intrusion alarm or body computer.
If I open/close a door and it adds another 100mA even with no lights enabled. Close door and back to 150mA.
I can kill the wiring to everything but the intrusion alarm or body computer so its looking like the problem is in this area.

Anyone have any experience with these?
Apart from the high consumption, everything works perfectly.
Click to expand...
The FSM talks about the dome cct remaining active for approx. 30 minutes after the last lock or ignition off cycle - some sort of a ready state. Could be functioning as designed and not faulty?
 
PADDO said:
The FSM talks about the dome cct remaining active for approx. 30 minutes after the last lock or ignition off cycle - some sort of a ready state. Could be functioning as designed and not faulty?
Click to expand...

REALLY?
Well that would be annoying as I'll be back to square one in diagnosing battery drain.

Whats 'FSM'?
 
WomblingFree said:
REALLY?
Well that would be annoying as I'll be back to square one in diagnosing battery drain.

Whats 'FSM'?
Click to expand...

Factory Service Manual, there is a 2004 downloadable version in the stickies.
Page 153 of the Electrical Wiring Diagram says:
Turn Off Function
When the ignition SW turned off and there is no change in the door courtesy SW for approx. 30 minute, the DOME relay is
turned off. The DOME relay is turned on again when any of the following conditions are met.
* Ignition SW is turned from OFF position to ACC or ON position
* Change to any door courtesy SW
* Driver or front passenger door is unlocked by the key or transmitter
Immediate Turn Off Function at Door Lock
When all the doors are closed, and the driver or front passenger door is locked by the key or transmitter, the DOME relay is
turned off, after approx. 80 seconds. However, when the illuminated entry system is operating, the DOME relay is turned off
after the operation is completed. the DOME relay is turned on again when any of the following conditions are met.
* Ignition SW is turned from OFF position to ACC or ON position
* Change to any door courtesy SW
* Driver or front passenger door is unlocked by the key or transmitter
Not sure if this is what you are seeing in your investigations or not.
 
Thanks Paddo

Yes that seems to about sum it up nicely.
So I'm left with a battery that goes flat after several weeks but has been replaced with no change.
Same results if charged with expensive multistage charger or the trucks alternator.

I think I'll have to buy a voltage logger and let it log the consumption over time and see what else is happening.
Now to find that manual...

Thanks for the help mate. You've been a big help.
Malcom
 
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