Chasing an Electrical Gremlin...

MadStang · Nov 24, 2011

Something tells me it's not the battery. it's sat for about 5.5 hours and is still at 12.5... Next thing to check will be the alternator.

g36 monkey · Nov 24, 2011

I think every part store has the little machine to put an alternator on and check it out. I know you don't want to, but it looks like you probably should.

MadStang · Nov 24, 2011

im gonna bring my PA alternator and my spare OEM to Vatozone after work. see if I can get both tested hopefully they both come back negative for AIDS.

framda · Nov 24, 2011

g36 monkey said:
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.

This is a wives tale. A real old one. There is nothing conductive to permit the discharge. It just isn't possible or true. I have left a lot of batts on concrete with no problems. Most of the time it is actually acid residue from the vent caps that permits electricity to flow between the two terminals with resistance that drains a little bit out . Got to keep the top clean. Also many people dont realize that even today the vent caps need to be pulled to check water levels. Refill with distilled only.

framda · Nov 24, 2011

MadStang said:
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

I saw a battery that had a broken plate inside. Sometimes the plate would stay in place and the batt would charge and discharge normally, other times the plate would lean over and touch another. This would cause it to short out and bubble up (making that smell). We figured it out when we drained the acid to replace it and saw one plate leaning on another. Another thought is that after a batt has been heavily discharged, they start to cause troubles. I have read that the lead doesn't like to come back out of the acid and bond to the plates as well. I have seen bad alts kill a batt and vice versa.

framda · Nov 24, 2011

MadStang said:
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... .

I want to put my batt in the trunk, I thought I saw a kit somewhere with everything for around $100. Any body see that?

g36 monkey · Nov 24, 2011

Thanks for clearing that up for me. Just something I had always heard lol. I thought it seemed pretty unlikely too.

MadStang · Nov 24, 2011

swapping in my oem alt right now. gonna get the PA tested tomorrow.

ttocs · Nov 24, 2011

framda said:
This is a wives tale. A real old one. There is nothing conductive to permit the discharge. It just isn't possible or true. I have left a lot of batts on concrete with no problems. Most of the time it is actually acid residue from the vent caps that permits electricity to flow between the two terminals with resistance that drains a little bit out . Got to keep the top clean. Also many people dont realize that even today the vent caps need to be pulled to check water levels. Refill with distilled only.

Sorry but batteries can go bad and "leak" voltage with nothing hooked up if they have been damaged in a number of different ways.

MadStang · Nov 24, 2011

Well, anyway, my alternator is buckled into the passenger seat. Gonna take it to Vatozone tomorrow.

framda · Nov 24, 2011

ttocs said:
Sorry but batteries can go bad and "leak" voltage with nothing hooked up if they have been damaged in a number of different ways.

Setting them on concrete does not drain the batt. Of course if a batt is damaged it will lose a charge. the two or three post I made specifically gave examples of that. Those batts are not discharging because they were set on concrete.

ttocs · Nov 24, 2011

setting them on concrete "should" not drain them, you are correct since there are no connections made to it. How ever once it has been deep cycled a few times, and becomes damaged then it CAN loose voltage just sitting there with nothing connected. This happened to my last battery in my truck that was less then a year old. My alarms battery went bad and was dragging the main battery down and kept killing it in little more then a week. After the 3-4 time charging it, it would then charge up as normal, test out as good but if you just left it there and came back a few hours later it was a few volts short. It can happen and does...

framda · Nov 25, 2011

ttocs said:
setting them on concrete "should" not drain them, you are correct since there are no connections made to it. How ever once it has been deep cycled a few times, and becomes damaged then it CAN loose voltage just sitting there with nothing connected. This happened to my last battery in my truck that was less then a year old. My alarms battery went bad and was dragging the main battery down and kept killing it in little more then a week. After the 3-4 time charging it, it would then charge up as normal, test out as good but if you just left it there and came back a few hours later it was a few volts short. It can happen and does...

This is common, it is what I was referring to in this post,

framda said:
I saw a battery that had a broken plate inside. Sometimes the plate would stay in place and the batt would charge and discharge normally, other times the plate would lean over and touch another. This would cause it to short out and bubble up (making that smell). We figured it out when we drained the acid to replace it and saw one plate leaning on another. Another thought is that after a batt has been heavily discharged, they start to cause troubles. I have read that the lead doesn't like to come back out of the acid and bond to the plates as well. I have seen bad alts kill a batt and vice versa.

MadStang · Nov 25, 2011

fun ride to work this morning, haha NOT. shifting at 3k and all I hear BOOM, crackle, pop, hiss as my rpms dropped to zero. Pushed the car the 3 blocks to work. when I got there it didn't fire on the first crank but it did the second, died when i gave it throttle, then fired third time and was okay... hopefully it starts when I leave today lol.

P0190. FRPS Circuit Malfunction. $130 later I'm picking up a new FRPS.

I'm just glad it wasnt my original thought, I thought I blew out a spark plug... sadly I kinda I hoped I blew a hole in the block, it'd give me a reason to dig into my tuition money lmao.

MadStang · Nov 26, 2011

UPDATE: Autozone can't test the alternator because there equipment doesn't work with the feet of the alternator. UGH. Oh well, I have my OEM replacement in and everything seems to be okay for now.

framda · Nov 26, 2011

They test for voltage output under a load. Same test I mentioned earlier by turning everything on and touching the voltmeter to the battery while the car is running.

MadStang · Dec 1, 2011

Okay problem is not the Alternator or Battery. My OEM spare is in the car and it's still got the battery drain... Whats funny is the car is perfectly fine when it's running, but if it sits for any extended period of time it just poops itself out. Any ideas?