jms
New Member
'07 Need New Alternator - Headlights and instrument panel flicker at idle
**EDIT**
So I got busy and never had time to actually work on this, but last week a CEL came on. Pulled the code and it was a low system voltage - had the alternator tested and turns out my initial hunch was correct - bad alternator.
So I'm now shopping around for alternators. Any advice on what to look for, or any brands to stay away from? Hoping to pay less than $150... there's a bunch of stuff on Ebay but not sure how to evaluate the quality. Thanks in advance!
** EDIT **
Hey everyone, I've had an "issue" with my jeep since I got it back in January. Whenever the jeep is at an idle (so the engine is around ~500 RPM) either when parked or at a stop light, I notice a lot of flicker in my headlights, instrument panel, radio display and anything else that lights up on the dashboard. Note that this only happens when at idle or very low engine RPM - when in higher gear and moving at 1000+ RPM, there's no flicker or any issues.
I'm looking for some advice to diagnose this problem. So far it hasn't actually caused any real issues, except just causing me anxiety that at some point it'll get worse.
One possibility I have considered is that there is a problem with the alternator. Maybe it's just not putting out enough power at low RPMs such as those experienced when the engine is at idle. Is there a way to test the alternator without paying a mechanic?
The other possibility I've considered is that the alternator is OK, but the engine is idling too low for what the alternator is designed for. Does anyone know what the correct idle speed a 3.7L automatic fully warmed up should be? The owners manual doesn't say, only that when warm the engine idle will decrease...
Any other ideas/suggestions/advice would be welcome too. Thanks!
**EDIT**
So I got busy and never had time to actually work on this, but last week a CEL came on. Pulled the code and it was a low system voltage - had the alternator tested and turns out my initial hunch was correct - bad alternator.
So I'm now shopping around for alternators. Any advice on what to look for, or any brands to stay away from? Hoping to pay less than $150... there's a bunch of stuff on Ebay but not sure how to evaluate the quality. Thanks in advance!
** EDIT **
Hey everyone, I've had an "issue" with my jeep since I got it back in January. Whenever the jeep is at an idle (so the engine is around ~500 RPM) either when parked or at a stop light, I notice a lot of flicker in my headlights, instrument panel, radio display and anything else that lights up on the dashboard. Note that this only happens when at idle or very low engine RPM - when in higher gear and moving at 1000+ RPM, there's no flicker or any issues.
I'm looking for some advice to diagnose this problem. So far it hasn't actually caused any real issues, except just causing me anxiety that at some point it'll get worse.
One possibility I have considered is that there is a problem with the alternator. Maybe it's just not putting out enough power at low RPMs such as those experienced when the engine is at idle. Is there a way to test the alternator without paying a mechanic?
The other possibility I've considered is that the alternator is OK, but the engine is idling too low for what the alternator is designed for. Does anyone know what the correct idle speed a 3.7L automatic fully warmed up should be? The owners manual doesn't say, only that when warm the engine idle will decrease...
Any other ideas/suggestions/advice would be welcome too. Thanks!
Last edited:
