what can kill the charging system

[thedadas1313]

so i have been posting about my wifes sunfire for a while now andf still no help. took it to a shop they said replace the alt. which i had already done. 105 amp rating putting out 50 amp. 11 to 12 volt charge. replaced the alt again. same thing. now you prolly already guess that i only replaced it a sceond time for giggles. but now im getting confused. the alt/generator is supposed to produce 13.5 to 14.5 volts of power off the main post return the charge tio the battery. which means as long as the generator is spnning fro the car running ti should always say 13 or 14 at that post. so why would it say 11 and the 12 then 13 then 11 then 13 then 12. what can kill the charging system. and please dont anyone say a bad battery conncection cause anyone who has ever worked on a car long enough knows that you can disconnect the battery completly with the car running and still read 14 volts. so im on my 3rd generator and just about to snap cause for some reason this doesnt make any sense. if ther eis an ecm expert who knows anything about how the programing for the generator works please send me something so i can find out if it is possible the the ecm can tell the generator which should always be at 13 to 14 to read 12. i think i just may blwo the damn thing up.

[89Sunbird]

Check for any cuts, crimps, rips or tears on the cables coming from the alternator...

[thedadas1313]

checked the wires. everything looked good. gonna run a jumper wire from the alt post the battery. thing i dont understand is why the alt would only read 12. shop told me what i already know. bad voltage. but the elctrical problem is causeing the bad voltage. but even wiht a short somewhere the alt should still read 13 to 14 with it spinning. is it even possible for a short in the 10 gauige wire running from the post to the battery to cause the alt to read 12 or 11 volts? whatever is happening is causeing all the dash lights to flicker. shop said they cant even test it until voltage and amperage is correct. but the elctrical problem is causeing the bad voltage so im in a loop of being lost. if you got any ideas id lvoe to hear them

[muff34]

What are the chances that the battery itself has shorted out inside and is frigging up the alt. Taking out the regulator in alt. Also read some where on the forums here that doing the battery disconnect thing on these newer cars are bad for the alt . Also read just recently where someone ended up changing the cables and problem was solved. Just my two cents

[thedadas1313]

no matter how good of a mechainc you are sometimes something comes along that just upsets you so much that you overlook something simple. in respoinse to the fact that we should not disconect the battery while running. i totoally agree adn understand why. the reason for staeing that was that an alt should always say 13 to 14 volts. what are the chances of the battery being bad and having the alt not chargepossible but not lickly. battery wont hold a charge but that alt sdhould still produce the voltage required. unlesss, under the damn battery tray where the body ground is you over look a small amount of corrosion on the wires and assume that being that the car is starting that the enigine itself is grounded. but lets say the motor isnt ground. well it appears that your cahrger will not produce the proper reading and the dash lighhts will flicker. will act like a bad starter sometimes and make you think the alt is bad the others. all over an 8 dollar battery cable. nevr underestimate thje small things. never assume that it is a good connection. always check and dont get ahead of yurself. one thing all mechanics do from time to time. this time was mine. corroed a little wher ei could see and under the tray corroded right through. making enough contact to start sometimes and work untill it loses ground and bam lights flicker alt reads eratic and you start to get real pissed..8 dollar part half hour of work. lesson for all experienced and new mechanics, dont get a head of yourself. just cause it visually looks good still check it thouroly to elimite that as the problem.

[stayfly40]

battery's don't short out the cells go bad and that's only if it is pushing to much amperage and not voltage. The battery is only there for back-up voltage the alternator is the big cheese in the car. it keeps recycling the energy and reusing it. the alt. is fried. get a new one.

[muff34]

Originally Posted by stayfly40

battery's don't short out the cells go bad and that's only if it is pushing to much amperage and not voltage. The battery is only there for back-up voltage the alternator is the big cheese in the car. it keeps recycling the energy and reusing it. the alt. is fried. get a new one.

oh really don`t short out .......hmmmm. Well what I`ve been told is that a battery with say 1000 cold cranking amps has the platelets inside that are much closer together than a battery with 700 CCA`s and as a result are more prone to getting jarred loose and possibly making contact thus resulting in a shorted cell