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3rd New Battery, Good Alternator, Supposedly No Shorts, Losing All Electrical Power

My batteries have somehow been getting drained. At first it was only if my car sat for several hours but lately it has been almost constant. The other day I was driving and for a second my speedometer went to zero, my seatbelt warning light came, and it seemed that my car lost power. After that second it kept driving normally again. It did this a few more times until eventually last week it completely lost all electrical power and stopped while I was driving. I had no lights or anything. It would not start again. I had to get it towed to Pep Boys where they said they would “diagnose” it. My car was there for 5 days before they finally just decided to replace the battery although I told them that that would be my 3rd new battery. After I got my car back it started doing the same thing. I had to once again take it back to Pep Boys because it’s close to my house so I could walk home. This time they said they found that the problem was with the idle air control (IAC) valve. They said that was the only problem and that there were no shorts or anything like that. I haven’t driven my car much yet so I don’t know if the problem is still going on but I’m assuming it is. I was just wondering if a problem with the IAC valve could actually drain the battery and/or cause a car to lose all electrical power? It doesn’t seem to me that these things would be related but I don’t know much about cars so I need some input from some people who do.

I see it’s a Dodge Neon but no year or mileage. They are wrong about no short circuits. They may be right but they don’t know for sure. The IAC may have indeed been bad.

Before fixing anything else, try to fix that bad ground connection that could cause electrical stuff to fail. My first step would be to rig a ground between the engine and the body. I used to have cables and alligator clips that I tried on some cars and I solved problems on six of them.

You don’t know much about cars and ,in my opinion, neither does Pep boys. about 20 years ago my father-in-law had his car towed to Pep Boys. They put in 3 different starters and called him to pick up his car because they couldn’t get it to start. I took him over with a chain to drag his car out of there and I listened to the horrible noises the car was making when attempting to start.
I asked them if they had checked for a cracked flywheel and they said they had no idea how to do that. The chrysler dealer across the street replaced the flywheel.

The fully drained battery is what keeps killing the batteries and fix the ground,maybe there is a broken wire or loose connector somewhere-Kevin

Are the batteries totally draining while the car is sitting overnight, or are you just suddenly losing power like someone turning off a switch? (or both)

2nd. question: How do you know you have a good alternator? How was it tested?

You need to find a good independent mechanic or even a dealer to diagnose the car properly. Ask friends, family or neighbors for a recommendation. Or use the mechanics finder tool on this site.

Good luck,

Ed B.

I also have to think the problem you are having isn’t due to a drained battery but a bad power connection to it. Power from the battery usually ties to a power distribution panel under the hood that is always hot to the battery. One leg from that panel connects to the ignition switch and that supplies power to the dash panel. The real trouble maker could be the ignition switch connections or in the main panel under the hood. If there is absolutly no power when this happens, like to the dome light or emergency flashers, then the trouble is near the main panel under the hood. Having a test light probe to check things with would help you pin the problem down.

I asked them if they had checked for a cracked flywheel and they said they had no idea how to do that. The chrysler dealer across the street replaced the flywheel.

My brother bought a brand new 78 Volare’…that came with a warped flywheel from the factory. After the starter was replaced the second time…something else was suspect…and that’s when the flywheel problem was found.

After all the main battery to car connections are checked, remove the fuse block and turn it over and carefully examine the back side for signs of melting or lose wires…Have a parasitic drain test performed…Stay away from Pep Boys…

start problems on dodge caravan and other electrical issues can be traced to a bad ground wire on top of trans. this grounds the motor to body.Check for corrosion on cable wire

Good ideas above. I very much doubt the IAC would be responsible for the electrical problem you are having. The IAC is a common source of poor idling in a lot of cars, so the mechanics there are probably experts at that fixing/replacing that part, and decided better to do something than nothing, so they did that, and then send you on your way. But you had no complaint about idling right? No harm for a general clean up of the IAC. But that’s why the electrical problem remains.

This will probably prove easy to fix, but the diagnosis may be a little tricky. A mechanic – either an inde or a dealership – with several years minimum of auto electrical system diagnosis experience will probably be necessary to get to the bottom of it. I think you’d serve yourself better to ask friends, coworkers, relatives etc for recommendations on who they use to fix their cars, esp if they own Dodges/GM’s.

Agree with everyone else, but has anyone checked the alternator ? If a section of the diode pack shorts, it will cause a severe drain on the battery with the key ( engine ) off as the diode pack is always connected to the battery and only allows current to flow one way ( to charge the battery ) when its good…if you have a shorted diode ( I have seen these ) the battery will charge but under a reduced amount and have a lot of AC ripple which can cause weird things to happen to modern cars.

When engine is shut off the bad ( shorted ) diode will cause a reverse flow into the alternator windings and kill a battery in a short time…I have seen reverse current flow in these situations from about 4 amps to 10 amps, which will kill a battery in a few hours. Keeping a car battery in this condition will cause it to sulphate and cannot be recovered and end up being junk…The alternator light may or may not come on with one diode being bad and still show 14 volts across the battery at idle…Also have them check the AC ripple…You said alternator is good…WHAT TESTS did they perform ?

Have them check for reverse current draw…My 89 Mustang GT draws about 8 milliamps to keep the ECU memory…This car sat for 3 months and started right up on the first try after having it in storage after I moved… You need to take this car to a independent mechanic and not a chain store. A lot of chain stores hire young mechanics to be or that are learning and know little to nothing when it comes to electrical issues, but can change starters / water pumps etc.

If you lived near me in FL I would be happy to troubleshoot it for nothing as I am now retired and did all the work on my cars, like putting in a new cam and lifters / push rods in my 67 Chevy 283 when GM had a bad run on soft camshafts in 66 & 67.( the number 6 cylinder exhaust cam was rounded out ).
I did send the heads out to be re-done for hardened valves and seats so it could run on unleaded gas without adding a lead substitute additive. You could see all the lead deposits on the valves.and on top of the cylinders.

The IAC valve has nothing to do with the electrical system…On my 89 GT the IAC valve has NO Power to it until the key is on the “ON” run position ( +5 volts )…Have someone check the current draw by connecting an ammeter between the battery and positive terminal with the engine “OFF” ( key off ) and should be no more than 50 to 75 milliamps at a worse case. Even with a 75 milliamp draw the battery should last at least 2 months before being depleted. If you ran this poor battery down many times it is toast. You need to get the problem fixed first or battery number 4 will become short order. Standard car batteries can only take a few deep discharge cycles before being ruined… You should not run a car battery down more than 15 % of its rated capacity. Deep cycle marine batteries are constructed different where they can take many deep discharge cycles and even here its advisable not to run them down no more that 70% of capacity and must be recharged within 48 hours or they will also sulphate.