Hey everyone, I’ve been noticing that my car has been idling lower than usual lately, and I’m wondering if a low or dying battery could be the culprit. Has anyone experienced something like this before? Could a weak battery actually cause low idle issues, or should I be looking at something else? Any insights would be appreciated!
I say yes. last week My bat went bad, rough idle, died at traffic lights, low cranking power. Put new batt in, problem fixxed!
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it runs fine above idle, but idle is at 200 rpms and when i rev it up and let off it idles down to nothing and dies out. that leads me to believe that the alt is putting plenty of juice for everything and making up for crappy bat.
it might be ur alternator not ur battery. My mustang was doing the same thing so I got a alternator test and the diodes were stuck open on the alternator draining the battery when the car was off.
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good idea, but i don’t think that’s it. it’s not really really sluggish on start up. just enough to notice. if the alt was bad wouldn’t all the electrical not work well while driving it? i’m gonna check the voltage on the bat and see what’s up.
if its stalling all the time at lights. try turning your ac on. it usually bumps the idle rpms a little bit. It has helped me in the past when i had a dieing battery.
it doesn’t help. it will still idle real low and the compressor kicks on/off very fast.
My battery crapped out a couple weeks ago. Now that I think about it, the idle is much smoother since I replaced the battery.
I ran in to this same problem last week after I left the lights on for a full weekend. I think its a combo of the battery being to low to run the alternator properly and the computer’s idel settings getting wiped. I charged the battery fully with a battery charger and my problem was solved. Hope that helps,
When the battery is low enough, the engine will barely idle and it can even stall. Have the battery load tested. The alternator depends on the battery to put out power so if the battery is dead or near dead, the alternator will be dead or near dead too.
Exactly what I did, problem solved. Weston Parker is completely correct about the stock alternator needing an “exciter current” from the battery to generate a magnetic field. Probably residual magnetism in the inductor allows for “self excitation” of the field winding when rotational speed is sufficient.
So Weston Parker are you saying if your battery dies the alternator is close behind in death? the ac trick works for me. If your clutch is turning on and off really fast its because your low on freon, and thats because you got a leak somewhere.
No, the alternator needs a strong 12V supply from the battery to function properly. Once the battery is recharged or replaced, and the alternator gets that steady 12V, it can generate full power again.
Older generators didn’t rely on battery voltage to operate, and some modern alternators, like the GM one-wire alternator, also don’t need it. However, most automotive alternators, including those in Jeeps, do require 12V from the battery, which is known as “exciter voltage.” If the battery is disconnected from a Jeep TJ, the engine will eventually stall. Without a battery or with a completely dead one, the Jeep can’t even be push-started. If jump-started, the engine will die once the external battery is removed if the original battery is missing or dead.