Electrical 1990 GT battery drain...

2007_Crown_Vic

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Aug 19, 2016
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Yeah, I was pretty let down when pulling the fuses didn't show that 0.17A draw decrease significantly, lol. I am lucky that my car is basically all stock and other than an aftermarket keyless entry (and maybe alarm?) nothing has been messed with. It does have an immobilizer installed. Hopefully nothing has gone weird with that.
 
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79pace

something stupid will fall out of my mouth
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Any time they install that have to pierce the protective coating on the wires and depending on how long ago it was installed it could possibly be an issue somewhere but it could be all good too. I have been debating installing a keyless entry back onto my car. I am so use to my daily drivers having keyless it seems weird to open my doors with a key anymore. lol.
 

2007_Crown_Vic

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I hope it isn't something to do with the keyless system or the immobilizer. If they are not run off any of the fuses pulled I don't even know how to check from a draw on those systems...
 

79pace

something stupid will fall out of my mouth
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Mine had its own fuse inline near the fuse panel. Yours probably has something similar wherever they are getting power from. Its going to either be under the hood somewhere near the solenoid or under the dash getting power behind the fuse panel but I bet it has an line fuse block.
 

2007_Crown_Vic

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Thanks! I will go hunting for it. That is basically the extent of my electrical skills... pulling fuses and reading a number, lol.
 

HemiRick

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Do you know anyone w a FLIR gun (heat camera) these are great for finding draws, whatever is consuming that current is warmer than everything around it.
 

KRUISR

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I would check that keyless entry/immobilizer. Added parts from long ago. Was it done right or has it deteriorated.
 

2007_Crown_Vic

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Do you know anyone w a FLIR gun (heat camera) these are great for finding draws, whatever is consuming that current is warmer than everything around it.
I was willing to go buy one cause I liked the idea, but apparently they will only detect one of a few amps or more. Mine is only 0.17 so it probably wont see it.

I'm going to see what I can find with the keyless entry and immobilizer. Hopefully I can find fuses for them
 

McFly2

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Normal parasitic draw normally 50ma. You have 170ma draw. More then normal but not excessive. Apparently you have not checked your battery with load to see if all cells are good. A local shop should be able to check your battery. The chain auto parts will check it for free. Take it out or drive it to get it checked if you are into it. I like this video for a summary of draw trouble shooting that might help.

View: https://www.youtube.com/watch?v=KF1gijj03_0
 
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2007_Crown_Vic

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Aug 19, 2016
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Normal parasitic draw normally 50ma. You have 170ma draw. More then normal but not excessive. Apparently you have not checked your battery with load to see if all cells are good. A local shop should be able to check your battery. The chain auto parts will check it for free. Take it out or drive it to get it checked if you are into it. I like this video for a summary of draw trouble shooting that might help.

View: https://www.youtube.com/watch?v=KF1gijj03_0

Lol, that is the exact video I used to get started. It helped a lot. I have a charger on the battery right now. I just want to see if it will take a full charge and hold one disconnected from the car.

I would love for it to be as simple as a bad battery, but unless a bad battery can cause it's own 170ma draw (maybe it can) I worry that the next battery I put in will just keep getting run down and damaged too.
 

79pace

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Once I resolved my drain issues my battery seemed good but wasnt. As I said it never showed full charge on the charger but if I drove the car every couple of days it was all fine but put a new optima in mine and have had no issues since. I think having a drain for so long and being put on the charger so often killed my battery. Would hold a charge for a couple of days and was fine if I drove it often but not if it set.
 

2007_Crown_Vic

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Ok, so battery is finally fully charged - meaning the charger switched over to "charged/maintaining". I unhooked that, disconnected the negative cable and got a reading of 12.79V on the battery. So I will wait a couple of days and check it again hoping it is still at or close to that.

I know when I get back from a drive if I check the battery voltage right away then come back a few days later (not just this car, seems to happen on lots of them) the reading is usually slightly less I assume from cooling off and just sitting a bit. Is there an acceptable level of drop from a battery fresh off a charger or should it stay basically the same?
 

2007_Crown_Vic

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So after a day of sitting it was down to 12.61V. About 8-10 hours later it was down to 12.55V. About a day after that it is at 12.5V. I will check one more time tomorrow morning, but it looks like it has more or less settled in around 12.5V if it only lost 0.05V in a day of sitting. So while it may not be perfect, I think the battery is at least decent, certainly good enough for starting a car in warm weather at least.

So I will keep looking around, mainly at the immobilizer and keyless entry/alarm system to see what I can figure out. Those areas seem to be the most likely to be causing this drain I think.
 

John Dirks Jr

there is enough sticking out to grab on to
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Im chasing a similar problem with my 92 lx now. Beginning with a full charge, the battery has gone low enough to not crank the engine after sitting for a week. I tested the resting amp draw and I get 20 milliamps. I know thats not excessive but just curious, could that draw be from the memory of the aftermarket radio head unit?

I have the battery charged up and disconnected now. Its at 12.6v and I will retest the voltage over the next few days to see how much the battery looses on its own.
 

manicmechanic007

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Batteries do not like to sit
Plan on replacing it if it sits for 4 to 6 months
In the house at 70 degrees it will last a little longer
 

manicmechanic007

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John your battery may just be getting a bit old and not holding a charge like it used to
Only a pretty new battery will maintain its charge for 2 weeks
10 days to 2 weeks is the spec for a car with 5 modules powering KAM (keep alive memory)
Your 92 should have only 3 draws but it is still 10 days to 2 weeks on a brand new battery
 

KRUISR

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My battery stays in the car. I will disconnect the negative if leaving it more than a couple weeks. It will sit out in the cold shop for 2-3 months disconnected, I hook it up and it fires right up everytime. My battery was new in 2017.
 

John Dirks Jr

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John your battery may just be getting a bit old and not holding a charge like it used to
Only a pretty new battery will maintain its charge for 2 weeks
10 days to 2 weeks is the spec for a car with 5 modules powering KAM (keep alive memory)
Your 92 should have only 3 draws but it is still 10 days to 2 weeks on a brand new battery
The battery is about 1 year old. I started at 12.6v battery charged and disconnected. 14 days later its a 12.48v. So the battery itself is ok. I'm gonna hook it back up and let it sit another week and check again. I think it's possible of one or two issues maybe.

1. The starter solenoid acted up where it would give nothing on the key turn. Turn back the key, wait a few seconds and try again and it would crank normally. Could be the ignition switch too. Perhaps one of those components had created and intermittent parasitic draw related to the intermittent no crank condition.

2. The rear hatch is difficult to close and requires a good slam to get latched, sometimes repeated slams. I suppose its possible that could cause a parasitic draw if the switch that turns on the interior lights isnt fully open when the tailgate is closed. I hope I can make an adjustment there for easy closing and proper switch engagement when latched.
 

manicmechanic007

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True story I am glad you are smart enough to know some of this stuff
The ignition switches get loose and quit working and or short out and start fire
Usually cause no draw though
50 to 85 milliamps is one spec for draw on a car like yours 200 is more like a new lincoln with 5 modules and a radio
Certainly it is the car dragging the battery down
You have checked the alternator for the field being energized right? Makes the alternator core magnetic