Chasing an Electrical Gremlin...

MadStang · Nov 23, 2011

okay I'm frustrated. I'm buying a multimeter tonight. someone give me a brief synopsis on how to use it.

From what I understand this is how it's done?
Disconnect positive, connect one multimeter lead to cable and one to the terminal. then check for draw more than x amount? (how much is x?). Then start pulling fuses one by one until the circuit is found with the draw.

any recommended tools for removing the fuses? i don't have the ford tool that pulls it...

ttocs · Nov 23, 2011

that is good so far. Your draw at idle should not be more then .3-.4 amps at the VERY most...

MadStang · Nov 23, 2011

ttocs said:
that is good so far. Your draw at idle should not be more then .3-.4 amps at the VERY most...

thanks Scott. this couldnt have come at a worse time.. biggest project of the semester and I'm gonna be out push starting my POS to get it going ughh... so stressed

ttocs · Nov 23, 2011

get a friend to help you by just sitting there watching the meter and then go in and start pullin fuses. It really will should not take as long to find the fuse as it does to disconnect the battery. The hard part is after that trying to figure out what specific part is draining it.

CC'S95GT · Nov 23, 2011

you can also watch for voltage drop. It's similar to amp draw only yoou don't need to disconnect the battery.
Just connect the volt meter to both pos and neg posts of the battery. and watch the voltage drop slowly.
Don't forget to ck things like vanity mirrors, trunk light, hood light,

ttocs · Nov 23, 2011

that only works for large current drops. A smaller one like he has been chasing probably will not show up.

MadStang · Nov 24, 2011

So my results. Car off sitting for 3 hours after I charged the battery again.

Positive Cable Lead to Negative Cable Lead = 3.5ohms
Negative Cable Lead to Negative Terminal = 12mA
Positive Cable Lead to Positive Terminal = 12.5mA

dunno what that means at all lol.

ttocs · Nov 24, 2011

thats not all that big of a drain really. How long does it need to sit before the battery is dead? Charge the battery outside of the car, then leave it out but check it out again 4-6 hrs later. I had a battery recently that kept dying but tested ok after a trickle charge. I took it to autozone where I got it and left it there for longer then I needed, and before I picked it up I asked them to check the voltage and if it tested ok to to a full test on it again. When they went to test the voltage with out anything hooked up it was already down to 11.5 volts.

D3VST8R96GT · Nov 24, 2011

wire fire ...insurance

delete after completion

MadStang · Nov 24, 2011

ttocs said:
thats not all that big of a drain really. How long does it need to sit before the battery is dead? Charge the battery outside of the car, then leave it out but check it out again 4-6 hrs later. I had a battery recently that kept dying but tested ok after a trickle charge. I took it to autozone where I got it and left it there for longer then I needed, and before I picked it up I asked them to check the voltage and if it tested ok to to a full test on it again. When they went to test the voltage with out anything hooked up it was already down to 11.5 volts.

two days ago it was 16 hours. id say on average24 hours and that thing is toast.

I'll check the battery today. I think the alternator is fine because it is charging the car perfectly fine when it's running.

D3VST8R96GT said:
wire fire ...insurance

delete after completion

and it's a wonder why no one actually posts here anymore...

g36 monkey · Nov 24, 2011

I like Scotts idea of checking the drain while its out. Just don't put it down on concrete, it drains it. Put it on a work bench or something. I am hoping its something like the battery though, not something more serious.

ttocs · Nov 24, 2011

like I said my last batt tested good off the charger but obviously if its dropping voltage just sitting there, there is something bigger wrong. You would need a higher amperage drop then that to kill it overnight or even in 16 hrs so I would suspect the batt as well if the car runs and charges fine.

MadStang · Nov 24, 2011

ttocs said:
like I said my last batt tested good off the charger but obviously if its dropping voltage just sitting there, there is something bigger wrong. You would need a higher amperage drop then that to kill it overnight or even in 16 hrs so I would suspect the batt as well if the car runs and charges fine.

is it still a possibility the alternator is overcharging the battery? I remember under a heavy load (2k rpms going up a steep hill) I had the sulfuric battery smell like rotten eggs. don't know if that was my battery dying out or if the voltage regulator is malfunctioning overcharging the batt

ttocs · Nov 24, 2011

sulfuric smell, no idea........ It could be over charging but that is something that a quick hook-up at autozone could tell you.

MadStang · Nov 24, 2011

true. I don't think they're open today though unfortunately lol

g36 monkey · Nov 24, 2011

Ha, thats probably true. At least its easy enough to take off and check.

MadStang · Nov 24, 2011

yeah, I'm gonna test the battery today and if it's fails the drain test then I won't have to worry about the alternator lol

g36 monkey · Nov 24, 2011

Sounds good. Really hoping it has to do with one of those two things though.

Easy, unfortunately they cost quite a bit. Probably my two least favorite things, absolute necessities, but super expensive and don't add anything special lol

ttocs · Nov 24, 2011

I am not totally convinced it is one or the other yet and not a bad connection somewhere. unfortunatly to test that you often have to go and replace the battery, just too many connections to trace and ensure they are good.

MadStang · Nov 24, 2011

g36 monkey said:
Sounds good. Really hoping it has to do with one of those two things though.

Easy, unfortunately they cost quite a bit. Probably my two least favorite things, absolute necessities, but super expensive and don't add anything special lol

unless you do a battery relocation at the same time, and the way it's looking right now.... I already have the box, just need a smaller battery to fit in it, then rewire that shit to behind the passenger seat...

ttocs said:
I am not totally convinced it is one or the other yet and not a bad connection somewhere. unfortunatly to test that you often have to go and replace the battery, just too many connections to trace and ensure they are good.

Well I'm just letting the battery chill for a bit. it's currently sitting at 12.5V so we'll see what it's at in a couple of hours.