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

Active Member
Aug 19, 2016
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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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Aug 19, 2016
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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

I'd be looking at jacking under the house
Jun 28, 2020
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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

5 Year Member
Apr 16, 2015
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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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Aug 19, 2016
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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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Nov 21, 2020
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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
 

2007_Crown_Vic

Active Member
Aug 19, 2016
122
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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

something stupid will fall out of my mouth
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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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Aug 19, 2016
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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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Aug 19, 2016
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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.