East fix and diagnosis----Sounds like the prob is the alternator---get it running--pull the neg terminal off the battery-while running--if it dies--it's the alt---dieing while driving is normally the alt failing and you run the batt out of juice. The batt may still be good and recoverable !---It's a DIY project----For the novice--here's some hints----WON'T START---headlights dim when trying to start or no headlights[dead battery]--what caused this? --ALTERNATOR OR BAD BATTERY--jump the car--pull the neg battery terminal while running--if it dies it's most likely the Alt. --WON'T START--headlights are good and do not dim while trying to start--most likely a starter--except with GM -VATS--Try banging the starter with something-- might get you on the road--heat and moisture exacerbate this problem---DIES WHILE RUNNING--esp at a stop --and won't crank afterward---usually begins to skip or miss before the total failure--That's an ALT !--As the weather changes to it's extremes, batteries go TU--Way cold or way hot , puts a lot of stress on them and they tend to fail more often in these conditions. I think you'll find your Prob is an Alternator-- LET US KNOW !! My last problem was a bear---figured it out, but not without these folk!!!---1000 bucks-- at a dealer--cost me .79 cents and one day to noodle it out!!!
Warning-- this doesn't always work and it's not recommended for newer computer controlled vehicles. Disconnecting the battery with it running causes the computer to think that the battery is completely dead, and usually it compensates by cranking the alternator to full output. This isn't good because it can cause power spikes that can fry your computer. Same reason that jump starting new vehicles is recommended that the car providing the boost be turned off... power spikes from the other car's alternator kicking it at high power can fry the computer on one or both cars!
Take the vehicle to a local auto parts. Take the battery out and take it in for a load test. If the battery has a problem, it will show up on a load test. They CAN hook up a dinky sorta tester to the battery with it in the car, but it can give less than accurate readings. I just went thru this myself yesterday. My folks minivan I'm borrowing to go to Indiana started dragging on starting, and would go very low overnight to the point of needing a boost. I figured, sure, it's the battery. Sunday after lunch I stopped at Oriellys and had them put the tester to it in the car. The guy farted with the tester and said, "crank it up" and I did... he said it was showing the battery was good, but the alternator had one leg of the diode bridge (rectifier bridge) out. Great... now instead of a $80 battery, it's a $180 alternator... SO, I take the thing over to my brother's shop and pull the alternator out. PITA on a Dodge minivan, lemme tell ya... Get it out, and run to lunch with the folks and then to get a new alternator. I have them put it on the alternator test machine, and sure enough, it comes back GOOD. He ran the test three times-- good, good, good. SO, it's the battery after all. Take the battery out of the van and take it walmart where it came from-- it's only 3 years old. He tests it-- BAD... shorted cell (what I figured it was-- 13 volts, but only 440 out of 660 CCA's... shorted cell for sure.) Price a new one and think I can do better at AutoZone or Oreilly... go to AZ, have them check the battery-- no good, shorted cell. Have them check the alternator too-- checks good. Went over to Oreilly (different store, different town) and have them check the battery-- bad- dead cell. Check the alternator-- tests good, he checks it twice. Buy the battery from them at a slightly better price. The "graybeard" who set up the alternator test and then turned it over to a younger guy came by and asked about it, and the kid told him it tested good. "Okay" he says, "but sometimes it's those CLUTCHES on the front of the alternator that goes bad-- the thing will test good in a test stand but will slip enough not to charge in the car". "Great" says I-- "why put a CLUTCH on an alternator?? that's the stupidest thing I've ever heard of??" "Makes it idle quieter" says the graybeard.. "Stupid Dodge"... says I... "Glad I'm a Ford man"... The graybeard looks at me humorously and says "They ALL have that now".
SO, I said, "can you fix the clutch or get a new one, or do you have to buy the whole alternator??" "whole new one" said the graybeard.... "Unless you take it to a shop that can change them out..."
Well, there was an alternator rebuilder in town, and at first my folks wanted to take it to them, until Dad called and found out they charge just as much for a rebuild job as to buy one at the parts house... So, we stop by there on the way out of town and I ask THEM to check it out. The guy checks it, runs a bench test, and comes back and tells me it's fine... shouldn't be a problem. BUT... "new vehicles don't have the alternator regulator in the alternator anymore-- it's in the vehicles' main powertrain/engine computer... and there's a LOT of stuff that can cause it to go wonky... a Dodge came in that had a faulty crank sensor and the computer wasn't reading the RPM on the engine as being high enough, so it turned off the field to the alternator-- IE wouldn't generate any power... no problem with the alternator itself, or even the computer... but the faulty sensor caused them both to go wonky... your problem is most likely different... no way to know until it's all tested together as a unit on the computer".
SO, my advice-- start with the battery. Test it. If the battery is good, you have bigger problems. If it's bad, replace it and see. If the battery is good, pull the alternator and have it bench tested at SEVERAL DIFFERENT STORES (and make sure when they test it that they punch in to the computer that it's THEIR brand... the computers are 'tilted' to show other brands are "faulty" and the house brand stuff is "good" more often than not). If the alternator is out, be prepared to pony up a couple Franklins... Merry Christmas!!! If not, then you probably need to just take it the mechanic and have them troubleshoot it...
later and good luck! OL JR
