discobandaid01 Posted December 7, 2014 Report Share Posted December 7, 2014 ok the other day got home and the brake battery and trans oil temp light came on..so bad alt..right swaped it out runs fin all light are normal but when i shut the thing off my battery light comes on and stays on even after i take the key out..so what the heck??? all fuses look good wires and battery connections look good even cut the positive wire back a bit cuz it looked a little gross..nothing is sticking out at me...the only thing that isnt the same as before is the new alt it plugs in the back and not the side like the original one that came out...so ??..ok so was looking and napa gave me a 60 amp vs. the 70 amp that was waht i took out..is this a big deal is this the problem? Quote Link to comment
datzenmike Posted December 8, 2014 Report Share Posted December 8, 2014 I hope you kept the original alternator. Go back and have them check that they replaced it with the correct one. Plugging in the back instead of the side? That's fine but obviously not a direct replacement. 60 vs. 70 amp? Higher is better because you have EFI and you need a good solid charge rate even at idle with high beams, heater fan on high, turn signals, wipers and heated seats on. Being 60 shouldn't be the cause of the light. The 60 instead of 70 and the placement of the plug says this is the wrong one. Your 'new' alternator is probably what we call 'bad in the box'. This is the what seems to be becoming more and more common today. Replacement starters, alternators and brake parts are crap with poor quality control made by $2.00 an hour workers in China. I would guess that the original replacement alternator from the dealer is over $250 so you get what you pay for. The factory alternators rarely fail and the only part to really wear out are the brushes inside. It's under $15 to replace them to find out. Quote Link to comment
discobandaid01 Posted December 8, 2014 Author Report Share Posted December 8, 2014 thank you for the help, and i had them order the right one..the 70 amp,, so you dont think that it is the issue? the light was never on before the alt went bad..just after i replaced the alt and only when the car is turn off ..did some wire checks checked for bad connections, corrosion, everything else..even the fuses.. so I'm stumped Quote Link to comment
datzenmike Posted December 8, 2014 Report Share Posted December 8, 2014 ok the other day got home and the brake battery and trans oil temp light came on..so bad alt..right Not sure of this diagnosis. A non charging alternator will usually show a RED charge light on the dash. This is the same one that comes on with the ignition but goes out when the engine starts. The brake battery trans oil temp light? Are these all separate lamps in the dash? The brake light should only come on if there is a failure in one of the hydraulic systems, the master cylinder reservoir is low or the emergency brake is on. The alternator should not impact this if it fails. Quote Link to comment
discobandaid01 Posted December 8, 2014 Author Report Share Posted December 8, 2014 true, but i did some digging around and the 3 lights coming on together is a symptom of a bad alt tested the alt by pulling the pos. battery cable while car was running and it killed the motor so replaced the alt..napa gave me a 60 amp telling me that was the right one..even though it didnt look the same..but it bolted up and the car ran no lights on..so pulled the pos. cable while running and it kept running..so i thought ok..fixed took it for a drive got back home shut it off and the battery light came on..so i Googled around found a similar post ..looked at other alt at other parts stores and they are all saying 70 amp ..so i guessed it had to be the issue since the alt was the only thing different ..but any other ideas guesses or educated guesses hell even a stab in the dark as to why the battery light comes on and stays on after i turn it off ..I'm all ears.. Quote Link to comment
discobandaid01 Posted December 10, 2014 Author Report Share Posted December 10, 2014 got the new replacement alt for "big rusty" (our sons pet name for our pathfinder)..this one is the 70 amp not the 60amp that napa gave me the first.. the battery light is gone..lol..dont know why the 60 amp alt would cause this oddity but replace it with the right one and problem solved..so fyi...dont put a 60 in your pathy if its an automatic trans..and thanks again for all the input guys.. Quote Link to comment
datzenmike Posted December 10, 2014 Report Share Posted December 10, 2014 Your 'new' alternator is probably what we call 'bad in the box'. This is the what seems to be becoming more and more common today. Replacement starters, alternators and brake parts are crap with poor quality control made by $2.00 an hour workers in China. 60 vs. 70 amps isn't the problem. The above probably is. 1 Quote Link to comment
datsunaholic Posted December 11, 2014 Report Share Posted December 11, 2014 The 60A alternator was bad out of the box. When the alt light is on with the ignition off, the diode trio is shorted (and it's discharging the battery through the alternator. The diodes are to prevent the alternator from becoming an electric motor when it isn't charging). I've had it happen more than once. 1 Quote Link to comment
banzai510(hainz) Posted December 11, 2014 Report Share Posted December 11, 2014 dont be pulling the battery cable while running. This worked fine on the older cars but dont do it.SP WITH LIGHTS ON OR HEATER IT WILL DIE If you have concernes make them ck the unit before you leave the STORE A 60 or 70 amper isnt the real issue I would think alot of part stores its RACE TO THE BOTTOM WHEN IT COMES TO PARTS 1 Quote Link to comment
discobandaid01 Posted December 13, 2014 Author Report Share Posted December 13, 2014 ohkay? not sure why you say not to pull the cable while running..could you give me some reason why not? Quote Link to comment
Alec 720 Posted December 13, 2014 Report Share Posted December 13, 2014 Possible spike overloading your computer or other electronics destroying them... Electrocution Proves nothing.. just because it runs, or dies doesn't mean your alt is good or bad. Quote Link to comment
datzenmike Posted December 13, 2014 Report Share Posted December 13, 2014 Removing one of the cables at idle should be ok as the output is quite low anyway. As mentioned on a newer computer driven vehicle the risk isn't worth it. As for running when disconnected it would show that the alternator is at least making enough power to run the engine but whether it is when revved up with lights and accessories on???? The 60A alternator was bad out of the box. When the alt light is on with the ignition off, the diode trio is shorted (and it's discharging the battery through the alternator. The diodes are to prevent the alternator from becoming an electric motor when it isn't charging). I've had it happen more than once. Occam's razor... 'The law of parsimony' states the simplest answer is likely the best. This is the most likely. Quote Link to comment
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