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My friend called me over today to take a look at her car which is having a weird issue. It’s a 2002 Kia Optima V6 w/ ~150k mi, engine was replaced ~6 months ago. Last week she started having some electrical anomalies (ABS light, radio not working sometimes, etc) but the car would still start and drive perfectly.
Now, it starts up fine and will run/drive for a few minutes but once the engine gets warmed up it completely dies all at once. The engine and entire electrical system, acts like it has a dead battery. Let it sit for an hour or so, come back and it’ll start fine and do the same thing.
Had the battery tested (it’s less than a year old) – Excellent. Tried another battery, no difference.
Had the alternator tested, tests good.
Checked main fuse / fuses in general, no problems there. Checked continuity and visually inspected the grounds, all seem fine. The battery/ground cables I could access all look fine, but I by no means have gone through the car wire by wire.
Any ideas would be greatly appreciated!
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But how would that kill the entire electrical system? Especially since she mentioned warning lights/electrical problems just a few days before this started I’m thinking it has to be wiring, and since the whole car dies it’s gotta be close to the battery. Her dad tried jumping the car with his and it idled for 15 minutes without any problems. So I guess I need to go through the ground wires more thoroughly tomorrow…
Connections are a big cause of issues like this. If you have a bad connection at the battery, or a bad body ground, it can cause those symptoms. Here’s a video you may find helpful. Also, it might not be a bad idea to check the operation of the ignition switch. I’ll also post a link to an article I wrote on dealing with electrical problems that might be helpful.
http://www.ericthecarguy.com/faq/solving-automotive-electrical-problems
[quote=”stiv625″ post=82767]My friend called me over today to take a look at her car which is having a weird issue. It’s a 2002 Kia Optima V6 w/ ~150k mi, engine was replaced ~6 months ago. Last week she started having some electrical anomalies (ABS light, radio not working sometimes, etc) but the car would still start and drive perfectly.
Now, it starts up fine and will run/drive for a few minutes but once the engine gets warmed up it completely dies all at once. The engine and entire electrical system, acts like it has a dead battery. Let it sit for an hour or so, come back and it’ll start fine and do the same thing.
Had the battery tested (it’s less than a year old) – Excellent. Tried another battery, no difference.
Had the alternator tested, tests good.
Checked main fuse / fuses in general, no problems there. Checked continuity and visually inspected the grounds, all seem fine. The battery/ground cables I could access all look fine, but I by no means have gone through the car wire by wire.
Any ideas would be greatly appreciated![/quote]
try doing a voltage drop test on the main battery cables, explained here
http://easyautodiagnostics.com/bad_starter_test/starter_oncar_tests_1.phpIt sounds like a unwanted resistance problem that is exacerbated by heat.
Okay cool, voltage drop should be very telling even if I might have a hard time catching something in that moment right when it dies. But I think it has something to do with the alternator, or the cable to it. Can alternators overheat or short out when hot?
Thanks for pointing me to good resources, particularly that video Eric. She mentioned she thought the guy who swapped the engine for them seemed “sketchy” so maybe there’s some sloppy wiring yet to be found. I’ll see what I find in the morning
I think I would start by looking at the main fuse panel in the cabin or any large plugs coming off it going to the engine compartment. Move, wiggle stuff around and see if it will start.
I played around with nearly every wire under the hood today after it got hot and died, not a single hint of life. So we’d just sit in the garage and drink beer with the ignition key on and after 20-60 minutes magically you’d hear everything click on and the radio start playing. Starts right up and 1-5 minutes later kaput, rinse and repeat all day…
If it really is heat related, one thing you can do is turn the key on, then use a heat gun on low setting, being careful not to get too close and melt anything, and warm up suspect components, see if warming any of them up causes everything to click off.
That might help you narrow down your list of suspects. I would probably concentrate on main electrical connections, and relays.
Sounds like it might be an ignition switch problem. I would get some good wiring diagrams and see what all these circuits are powered from. (Which is probably the ignition switch.)
I woke up this morning to a text from my friend saying don’t worry bout the car, its your birthday, its cold outside, my parents offered to pay for a mechanic, I need my car back asap, etc. I wasn’t going to go for that and was even more determined.
I got a big hint from mother nature. It was like 28 this morning instead of 58 working yesterday and as I was probing various cables and circuits I noticed the car ran much much longer without cutting off. Okay, definitely temperature related. What gets hot? Exhaust gets hot. Duh. Sure enough I climbed underneath and took some stuff apart for better access and there it was. The alternator battery cable melted to the rear bank exhaust. Not to mention 2″ from that I found a cut ground wire under the intake manifold. So I swapped the entire negative battery cable with a spare i had and made all new grounds. 100 miles later absolutely no problems. I obsessively routed the new cable with like 10 zip ties.
I’m still not sure I understand electronically the explanation. Exhaust would just give it another ground? Or all the other grounds were too poor / small to power it? Or something overheated from the cable and cut power for safety? Wish I understood how to catch this with a multimeter…
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