Car won't start after disconnecting battery cables

[pistolonmyside]

PLEASE READ!!! It's been a year and a half, really need help..
Hi, here's my problem.
Specs of car are
2000 Mazda 626, LX V6

Now, about a year & a half ago my father went to start the car, he was going to take it to the shop & get a new battery & see why the car kept swelling the battery up & making it so hot. So he takes the battery cables off (so he could get to the mechanic without the battery swelling up/exploding) which he's done countless times in the past, but this time when he did it, the headlights flashed, windshield wipers came on & the car Reved down until it was off. From then on it hasn't been able to start.

Windshield wipers do not work
Turn signals do not work
Car will crank but not start
Fuel pump does not engage, when you out the key in, the car beeps & nothing on the dash lights up (except for door open indicator), and when you turn the key to the ON position, nothing else happens it just sits there beeping fast instead of going to the 6 beep sequence then stopping.. Fuel pump doesn't engage. Wipers don't work nor do turn signals. The car will crank but not turn over. Now, it was up until this point that me and him thought it was okay to disconnect the battery while the car was running as the alternator would take over.. After this happened I did some research and learned that the battery acts as a capacitor and limits voltage spikes. So, yeah, it was a dumb move. Any idea on what the hell happened!? Literally I've searched the Internet hundreds of times with different wording & no one else in the entire planet has ever had this happen!? I can't find ONE other person with this problem. It's like everyone is clueless. &I no we haven't taken it to the mechanic as it costs money to tow it there and be looked at.. Haven't tried a new battery, but we have tried jumping it with another car which acts as a new battery (as the engine cranks & the indoor lights are bright) so we definitely know it's not the battery.

So rundown
-tried disconnecting battery cables while car was running
-car shut off
-won't start now
-dash doesn't work, can't see mileage or anything else (fuel gauge etc)
-cranks, doesn't start
- fuel pump makes no noise
- beeping sequence stays same when key is inserted into the ignition

Please help!

 

[Kelgrin]

While doing your research on why you are not supposed to disconnect the battery from a running vehicle any more, I am sure that you learned that there are a fair number of electronics in cars now. You said your car was a 2000, so it should have what's called a PCM. The PCM acts as the brain of the car. It controls many aspects of the car, from the firing of injectors to the lights on your dash. If the PCM has been fried by a voltage spike, it would explain why your fuel pump does not engage and many of the electrically controlled features of the car (dash, wipers, etc..) no longer work. I cannot tell you how to test this theory, but i think it is the most likely cause of the problems you have described. As for the battery, if the car has done this to other batteries in the past, I would investigate the alternator. Its possible a faulty alternator could be over charging the batteries, causing them to fail. If the battery you talk about in your post was the first one, then it was probably just the battery. If you live in a cold climate and your battery was dead over night it could have frozen, causing damage to the battery. This damage wouldn't necessarily cause the battery to fail right away, but the battery would fail eventually, and possibly in the method you described above.

 

[Rheotome]

I can't tell you what's going on now, but I'm fairly sure that the initial problem was the battery was being overcharged.This would be caused by the voltage regulator not working correctly. Most modern systems have the Voltage Reg. built into the alternator, (it could be separate also). Sometimes they are externally replaceable, but usually not. You have to replace/rebuild the alternator, and if the battery is "cooked" replace that too.
I fear your current problems are more electronic in nature, caused probably by an overvoltage condition, which may have damaged some sort of control module. I can't offer any more guidance other than you will need to sort out the charging system before the other issues can be diagnosed.

 

[pistolonmyside]

While doing your research on why you are not supposed to disconnect the battery from a running vehicle any more, I am sure that you learned that there are a fair number of electronics in cars now. You said your car was a 2000, so it should have what's called a PCM. The PCM acts as the brain of the car. It controls many aspects of the car, from the firing of injectors to the lights on your dash. If the PCM has been fried by a voltage spike, it would explain why your fuel pump does not engage and many of the electrically controlled features of the car (dash, wipers, etc..) no longer work. I cannot tell you how to test this theory, but i think it is the most likely cause of the problems you have described. As for the battery, if the car has done this to other batteries in the past, I would investigate the alternator. Its possible a faulty alternator could be over charging the batteries, causing them to fail. If the battery you talk about in your post was the first one, then it was probably just the battery. If you live in a cold climate and your battery was dead over night it could have frozen, causing damage to the battery. This damage wouldn't necessarily cause the battery to fail right away, but the battery would fail eventually, and possibly in the method you described above.

Thank you so much for the detailed reply, I will definitely do some research on the PCM tomorrow. & this is like the 3rd alternator btw.

 

[pistolonmyside]

The main 100A fuse is not blown, so could it have skipped the fuse and blown the PCM? but the 10a "engine control system" fuse under the dash (on driver side) and so is the air bag system/abs fuse. Got a new battery, Replaced the 10a engine control fuse and the abs/air bag with the same one, & both blew when I put the key in the ignition and waited about a couple seconds in the on position. Car just cranks.. The beeping on the dash was definitely different when the key was in the ON position for about 2 seconds before it blew. Then it returned to the fast beeping no matter what position. Replaced it with a 15a fuse, blew that one too and the same thing. I don't wanna put a 20a fuse or something ridiculous and start a fire or something. What could be causing the fuse to blow when I put the key in the on position? (Btw, I'm 98% sure it blew in the on position though the second time it may have blown when I cranked it). Any ideas? A short? Wiring problem? Something else damaged from what my father did? AC doesn't work, radio doesn't work, headlights don't work. Trunk light and doors open light work. Gauges don't move. Very confusing.

 

[eyesofthetauren]

Hello, I think (as my father will also do) that you should buy a new battery.

I find this the best solution among all others.

Greetings.

 

[pistolonmyside]

I am beyond imagination shocked. So, the car started just an hour ago. this spanish guy that has always wanted to buy my dads honda civic came buy and asked if he could buy it again, and my dad laughed and said his friend was borrowing it from him right now etc. so my dad asks if he knows anything about mazda's.. he says oh yeah man. so my dad explains the problem to him.. this guy opens the driver door and asks for the key, he puts the key in the ignition, turns it and it cranks were like yeah see. and so he gets on his knees, and without looking at the fuse diagram starts pulling fuses and me and my dad are looking at eachother like hm. so then the dashboard lights, headlights, windshield wipers and gauges come on - me and my dad look at each other amazed and say "thats never happened what did you do?" he goes "hold on man" he gets in the car and cranks it a couple times, the car starts and runs momentarily for about 3 seconds and dies. me and my dad look at eachother in amazement and ask him what he did, and he says "you got any gas?" without a word me and my dad run into the garage looking for a gas can and bring one to him, he pours it directly in the engine bay in the throttle thing, and he says watch this, he turns the key, the gauges and all light up and he cranks it.. the car starts. the car runs for about 10 seconds and sounds perfect. me and my dad are amazed. he says "you have a bad fuel pump". we do the gas trick a couple more times to see it run and make sure it wasnt just a dream. he says he can replace the fuel pump for us for cheap. the windshield wipers would not turn off and slight smoke did come from the cabin. he said we probably have a short in a ground-wire somewhere causing it to smoke and for the electronics to act funny and thats why the fuses were blowing. so, were going to tow the car to his house and hes gonna help us fix it. we are completely stunned. this guy hasnt showed up but twice in the last 7-8 years, and today, out of the blue, the same day me and my dad randomly decided to fix the battery connector cables and buy a new battery and fuses, he shows up. what are the chances? and he says he has the same engine in his mazda suv. what are the chances? we are so shocked. the car hasnt run in a year and a half, and randomly today we decide to mess with it. the SAME day he decides to show up and ask if he can buy the honda for the first time in at least 2 years. wow. If we didn't believe in God before, we sure as hell do now LOL.

 

[eyesofthetauren]

LEGENDARY

 

[pistolonmyside]

havent got around to do anything yet.. bump.. i posted on yahoo answers and someone told me the car was probably totaled as the headlights dont work and i saw smoke etc. but idk, i have no idea what i should do?! replace the fuel pump, and try to have joel fix the shorted/melted wire that keeps blowing fuses, and then have him diagnose the alternator or why the original battery was swelling up? or leave it alone and buy a different car. i really like this car and i do want it but im scared to invest. what should i do?

 

[pistolonmyside]

bump

 

[pistolonmyside]

bump..

 

[pistolonmyside]

bump

 

[nick956]

I would personally determine if the car is worth keeping and if you are track down that short circuit in the wiring because from prior experience we had a VW beetle that a wire came loose in the window regulator harness and shorted to the door frame thus smoking and then shorting out the battery as well and making that sucker hot and swollen. We did tape up the wire that was causing the problems and then installled a new battery and reset the ecm and pcm module and the car was like new and no problems again.

 

[pistolonmyside]

I would personally determine if the car is worth keeping and if you are track down that short circuit in the wiring because from prior experience we had a VW beetle that a wire came loose in the window regulator harness and shorted to the door frame thus smoking and then shorting out the battery as well and making that sucker hot and swollen. We did tape up the wire that was causing the problems and then installled a new battery and reset the ecm and pcm module and the car was like new and no problems again.

thanks for the suggestion - that makes me think that the short was in the car BEFORE he disconnected the bat cables.

 

[RedGoldman]

Did you try to change the Ignition Switch?
I had a similar problem, the car won't start, after calling a few professionals locksmith companies that was expert in auto locksmith, one of them just suggested to change the Ignition Switch myself, he told me to search on Ebay the part, like this one, its quite cheap and really simple to change and it did the job, the car came back to normal and started with no problem.