D90 battery drain?

[sharknet]

Something seems to be draining the battery slowly - i checked the obvious ie: door lights not on- anyone know of an easy way to trace this down? thanks fb

[evilfij]

Measure amps across each fuse.

[sharknet]

thanks ron - sorry to ask but could you describe how i can do that? fb

[Mike Hippert]

Frank, how long does it take to drain it? The clock in my 90 draws a bit of current, not enough to kill the batt overnight but maybe over a week or so. How much do you know about multi meters?

[sharknet]

hey mike - it takes several days of sitting - i bet that it- i have a d90 soft top and 110 they don't have this problem though -

not a lot about multi meters but i'm a quick learner - what do you suggest? thanks fb

[Mike Hippert]

Well, if you get a meter that can measure current then you can use it to find out what circuit is causing the battery drain.

To measure the current with most meters you:

1: remove the negative battery cable

2: attach the red lead of the meter to the black battery cable you just took off

3: connect the black lead of the meter to the negative (-) post on the battery

4: meesure away! The meter must be in DC current (Amps) and on most meters you need to plug the red lead into a differnt spot on the meter then the spot for measuring Volts and ohms.

5: Note the starting current, then remove fuses from the fuse box noting what drops the current the most.

6: report back what you find

Clear as mud?

[sharknet]

hey mike - thanks for the detailed instructions! i'll get on that tonight and let you know what i find - thanks again-fb

[sharknet]

Ok mike - here is what i found out - i believe i measured in amp correctly - i pulled a fuse one at a time and recorded the amps per - starting with the top row left to right:

178 166 184 --> to the end


bottom row right to left:

184 30.4 184 --> to the end going the opposite direction from the top row

i'm guessing the 30.4 is a problem- in the manual it corresponds to the radio (19) and i am restoring the interior and one of the first things i did was take out the console and disconnect the radio - could i have disconnected it still on or something? any help is greatly appreciated and thanks for your instructions on how to measure current -they were great -fb

[Mike Hippert]

HMMM, looking at my manual there should be no power going to F19 when your 90 is turned off. Try measuring the voltage on the fuse with your 90 turned off. Put the red lead from the meter on the metal part of the fuse that is showing when the fuse is plugged in, then connect the black meter lead to the metal screw holding the fusebox in place. With your 90 off you should measure 0 with it on you should measure 13.5 volts. I'm going to measure a few things tommorrow just to confirm.

[sharknet]

ok i went out and measured - 12.53 volts with no key in the ignition - everything off - which is how i measured before as well - i think i remember that the radio was able to work with the vehicle off - neither of my other two defenders are this way so maybe the previous owner changed it? do you think this is the problem?

[Davis]

That may be part of the problem, but from the draw you are experiencing, I don't think it is everything. What the PO may have done is reversed the ignition wire and constant voltage wire connections to the radio. That is easy enough to fix. If you find this to be the case, then reverse it and recheck the amperage draw.

[Mike Hippert]

OK just looked at my current draw and about 135 mA. My radio fuse is at 0 Volts when off, so that is one of your problems. I also found my radio draws close to 75 mA when off, my hazards draw about 30 mA when off (odd as this may seem to some, but my 90 has seen some water so I'm not too surprised) and lastly my clock draws about 30 mA or so. So if you have no radio then you should be drawing I would say around 30 mA like you found when you pulled the radio fuse. I would trace the wire powering the fuse back to it's source of 12 volts and try and fix it. I think the wire is white/orange.

[pendy]

While you are at it call me about the ARB bumper. If you are not selling it now then I need to know.

Jim Pendleton