Voltage appears to dip at idle
#1
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Voltage appears to dip at idle
1991 LS400 just bought from my brother-in-law (sic)! I just replaced the air conditioning/time module (blacked out LED) with a refurbished part from a guy in California (who apparently has done a lot of these) - new LED, new bulbs behind switches.
The problem I have is that at low idle - at a stop at red light, etc, the radio occasionally crackles and flickers off and on and the A/C fan motor dips. At night the lights grow dimmer at idle. Everything's fine with higher rpms.
I was thinking the alternator (and internal voltage regulator). Had it checked. 14.25 v. I replaced it anyway with a new one. Now it's pushing 14.5v. But still the same phenomenon.
I called the electronics guy about the A/C/time module. He suggested a poor battery. I'll have that load tested tomorrow. But does the car pull from the battery at low idles?
Any ideas would be greatly appreciated. This problem is not the end of the world, but it is annoying.
The problem I have is that at low idle - at a stop at red light, etc, the radio occasionally crackles and flickers off and on and the A/C fan motor dips. At night the lights grow dimmer at idle. Everything's fine with higher rpms.
I was thinking the alternator (and internal voltage regulator). Had it checked. 14.25 v. I replaced it anyway with a new one. Now it's pushing 14.5v. But still the same phenomenon.
I called the electronics guy about the A/C/time module. He suggested a poor battery. I'll have that load tested tomorrow. But does the car pull from the battery at low idles?
Any ideas would be greatly appreciated. This problem is not the end of the world, but it is annoying.
#3
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I haven't had a good chance to wrap my head around this, but like you said your pulling enough voltage at idle, which is normally around 14.5, so your OK there. A poor battery would do that, however I'm not sure why it only appears at idle, and not starting or on any high load situations. There could also be a major draw on the battery somewhere, or something that is taking away power from that circuit. Sorry, I was no help.
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PureDrifter, Thanks for the quick reply. Not sure about the idle rpm speed. But it happens when the needle drops to zero. Slightly touching the accelerator or revving the engine for a little bit stops it.
But this doesn't happen all of the time.
3UZFTE,
Thank you too. Keep thinking. I and my mechanic are baffled.
Best,
Wes
But this doesn't happen all of the time.
3UZFTE,
Thank you too. Keep thinking. I and my mechanic are baffled.
Best,
Wes
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dandare
LS - 1st and 2nd Gen (1990-2000)
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01-29-16 04:09 PM