Parasitic Battery Drain on a 93 Shadow

[chryguy]

Alrighty then,

I have a .1 amp draw (103.6 mA) on my "dome light" circuit (fuse 13).
Keeps killing the battery if I leave it sit for any appreciable amount of time. It has actually had several batteries in it, and it has kicked them all in the jewels...

This draw is measured while the radio is disconnected, the dome light bulb is out, and after the courtesy light goes out around the key.

I have confirmed the hatch light is out, as is the glove compartment light while measuring this amp draw.

Pulling fuse 13 stops the power draw completely...0.00 power draw.

I don't have a P-body factory service manual, only a Haynes...and the wiring diagrams in those are useless.

A few random thoughts... Rare deals can always be seen on the Kroger Weekly Ad.

I don't think it's the relay for the key illumination light. It works as it's supposed to, turning on the light for about 10 secs, then turning it off. Uses approx .08 of an amp when it's on.

The wiring by the dome light looks fine. No signs of overheating or scuffed/torn insulation.


What else is on this circuit?

As usual, Thanks in advance for any ideas or info...

CG

[shackwrrr]

Visor mirrors. Open one up while testing, if it doesn't change then you found it

[ajakeski]

My 87 GLHS has developed the same issue. I'll have to track it down in the spring.

[shadow88]

To find out any other circuits that might be tied into fuse 13. Start the car, remove fuse 13 and see what doesn't work. there could be more than dome and visor lamps.

[RoadWarrior222]

Go round all the door switches, they usually actuate against a rubber bumper, sometimes those get damaged, develop a dent or fall out with the result that the switch is "half c0cked" when the door is closed. Also could be due to a door not sitting right or being bent/twisted. Also they can stick in the open position, punch the rubber insert through the panel, and corrode up inside, such that they're in partial contact all the time, but may flash the interior lights when you go over a bump. Sometimes they stick half actuated, but because of the position of them on the corner of the door, actually hold the door 1/8 or so off closing at that corner, often unnoticed...

[4 l-bodies]

89 FSM lists circuit 13 5 amp fuse
fuel gage, low oil and low temp gage, brake warning lamp, seatbelt warning lamp, seatbelt buzzer, oil pressure lamp, speed control, gate ajar, check engine lamp,
I've had 2) 89's P-bodies have glove box light kill batteries.
Hope this helps,
Todd

[chryguy]

OK, checked a couple things,

She's a stripper (Oh Baby!), so she doesn't have visor mirrors.

So far, I know the radio is on that circuit, but I have it unplugged during testing.

RW222 might be on to something...
Although the switches look fine, and the dome light never comes on when I'm driving...
When I open the door during testing, the draw jumps up .3 of an amp, even though the dome light bulb is out of the fixture...
The .3 amp draw can be replicated by pressing the door switch in and out, so it's definitely the door switch or something it activates.

Seems strange that the "empty" (no bulb) circuit would use power...

The dome light and hatch light draw around 1.1 amps each, so it's not the hatch light coming on when the door opens.

So, to clarify, the draw jumps from .1, to .48...(.08 being the key illumination light) when the drivers door is opened.

Pulled the glove compartment bulb just to make sure...still pulling .1 of an amp with the drivers door closed.

CG

[raccoon]

try removing the time delay relay.

[chryguy]

Finally started back on this mystery...

Pulled out the time delay relay, no change. Just for yucks pulled all the relays, no change.

Pulled the door switches out and disconnected them. They looked fine, no change.

Even though there was no change when the radio was completely disconnected, I swapped in a different radio.

As an aside, wondering why I have a "radio" fuse when the radio is controlled by the "dome light" fuse?

Andy, did you ever trace yours?

CG

[cordes]

Wow, that's a real doozy.

[rampant150]

Not sure if this helps:




Looks like the power mirror switch has a feed from the dome light?

[raccoon]

http://www.allpar.com/forums/topic/8...-lamps-fuse-2/

tachometer module?

[chryguy]

Thanks everybody,

I was reading that allpar article with hope till it came to the solution...

Since the Shadow is a base model, it doesn't have a tach.

I'm gonna guess that without a tach there would be no module since it would be located on the cluster.

This Shadow was ordered with nothing...power brakes, steering and AC are the only creature comforts on it.

Manual trans, mirrors, windows, locks...so I guess that makes it...easier(?)...to diagnose.

Uh huh...that's what I keep telling myself...

At $8 bucks apiece I'm leaning towards putting-in new "jamb switches"...just to eliminate that possibility...but I don't think they're bad.


Thanks again,
CG

[Dodge Aries K]

Radio uses the "dome light" circuit to keep the clock and station memory going. The "radio" fuse is to power the radio up when the ignition is on.

My old 92 Shadow had an odd issue. It was under the carpet on the driver side front floor. The wiring there corroded and caused all sorts of issues with the interior lights and draining the battery faster than it should. I'd check that out. Chrysler was too cheap to actually splice that joint correctly so it corroded up.

[marc]

How's the battery? I ask this because a 103ma draw would take about 40 days to discharge a battery rated at 600CCA. 103 ma draw is a little high, most new cars are around 50ma.

[chryguy]

All three of the batteries that it nearly killed were, and still are, working well in other vehicles. Each was at least 550CA or better. But...none were "brand new" batteries, so that may have contributed to their discharging.

In reality, it took less than 2 weeks of that .01 amp draw to make them unable to start the TBI engine.

CG

[marc]

You can try monitoring the voltage with a DMV, pull the #13 fuse and check the voltage. Check it in a few more days to see if its gone down any. If the voltage stays the same, you are on the right track. Don't drive without the fuse, I think the brake lights are on that circuit also. I've seen dome lights in cars staying on after a heavy rain, going off after it dries out just as Dodge Aries K mention.

[chryguy]

Update,

First, although the Shadow is stripped, it IS an ES model...so it DOES have a tach (DUH).

The tach IS on the same circuit as the radio and dome light...so, I think raccoon's guess of tach module is correct. I have not pulled the dash yet to test it though...

On to tonight's truckload of weirdness...

Got in the car after driving it around today. Temp is somewhere around zero.

First thing I notice is I seem to have lost a dash cluster bulb...no wait...several bulbs?

Next I notice the gauges are all pegged and not moving...

Had a quarter tank of fuel...now it's pegged full...temp gauge is completely pegged to the right...volt meter pegged to the left.
Tach is stuck at 2K, speedo is at zero...and I'm moving.

I stop, shut off the car and try a re-start...no difference.

While fueling, I'm fiddling around with stuff and I notice I can get the gauge needles to move by using the dimmer function on the headlight switch.
If I completely turn the dash lights off, the gauges go back to their normal ranges, but still seem...not quite right.
The exceptions are, the tach, which moves now...kind of flitting and twitching around with no logic or purpose...and the speedo which seems ok.
Turn up the dash lights and the speedo dies, tach freezes, and everything goes for the corners.

Get home, try several re-starts, playing with headlight switch...nothing seems to affect it.

Finally, I pull the fuse for the tach module/dome light/etc to kill the power and then put it back in...

Everything back to normal!

I'm guessing the tach module had some kind of ground crisis and threw everything into a tizzy...

I think I will be keeping my eye out for a new dash cluster.


CG

[cordes]

This is a wild one. Glad to hear that it seems normal now.

[chryguy]

Thanks,

Yes, quite weird...

When I got home and finally pulled the fuse, it was running at the time...and it pinned the tach at 2k. I had to shut it off and reinsert the fuse to get it to drop to zero.
That's when I did the restart and everything went back to normal.

Like you said Brian, just glad it's back to mostly normal now...

CG