Flickering dash lights?

Post by **jblackburn** » 10 Jan 2010, 10:17

I'm wondering if anyone has ever seen this before.

At night time, with nothing else but the headlights running, at idle, I can see my dash lights/interior lights sort of flickering. As soon as I touch the gas pedal and the RPMs increase, no more flickering.

Driving back from Louisville last night, I managed to find my way down some snow-covered back roads - thanks Garmin

. It was just me and my little car out there against like 4" of snow on twisty back roads. It was nothing short of great, but I did notice that when the ABS/TRACS system would activate, the headlights would dim slightly while it was working its magic (foot not on the gas of course). Maybe that's normal, I've never really noticed.

I'm thinking my alternator is on its way out. I haven't had a chance to check battery cables or anything, but the RPM-specific fluctuating seems to suggest that to me. Any ideas anyone?

Here's the best video I have of what I was talking about before I left
http://www.youtube.com/watch?v=ySI-UmqSqMw

You'll probably have to look very closely and watch it multiple times - you can sort of see the fluctuating in the bottom display panel (yes I know my light's burned out), I'm sorry all I had was my ipod video camera. I'll try to take another video tonight.

Post by **jblackburn** » 10 Jan 2010, 10:54

You know, I hate youtube anymore.

Try this one: http://s105.photobucket.com/albums/m214 ... G_0006.flv

I'll try to get a better video once it's dark again tonight.

Post by **billofdurham** » 10 Jan 2010, 12:36

Usually flickering dash lights are the first signs of an alternator going bad.

Check, and clean if necessary, the battery leads paying special attention to the contact between the negative lead and the frame. If they are OK test the alternator. If the alternator and regulator check out OK then a battery load test is the next thing to do.

Bill.

osmium · Post by **osmium** » 10 Jan 2010, 13:11

billofdurham wrote:Usually flickering dash lights are the first signs of an alternator going bad.

Check, and clean if necessary, the battery leads paying special attention to the contact between the negative lead and the frame. If they are OK test the alternator. If the alternator and regulator check out OK then a battery load test is the next thing to do.

Bill.

+1

I had those exact symptoms on an old Corolla and it was the alternator.

-os

Post by **jblackburn** » 10 Jan 2010, 13:26

Yeah, it's kinda what I was figuring. I've had one go on a Honda and a Buick, but they both whined something awful.

I had the battery/alternator tested today at Advance. The battery's fine, but a little low on charge - 12.1V, 353 cranking amps out of the rated 590, but it's also 5 years old and cold out.

The cables all look fine - I cleaned away a bit of corrosion a few months ago, and it hasn't built up much.

The alternator is charging at 13.1V under no load, and 13V under load (high beams, heater fan on). That was done holding the idle ~ 1500 rpms, not at the 900 where I'm noticing the lights. Seems a bit low to me with the battery kinda low on charge like that.

850 Turbo1 · Post by **850 Turbo1** » 10 Jan 2010, 13:35

That's good thinking having the parts store test things out...just make sure you get a knowlegable techie to do it..else you'll get told the opposite of the reality

!

Post by **MNCO1** » 10 Jan 2010, 15:16

Put in an after market radio, an Eclipse model and I noticed that the lights on the radio flicker if I dimmed down the dash even a little. Emailed the Eclipsed folks and they said the radio wasn't designed to work with a dimmer function. It needs a minimum supply of 10 watts, I believe. I would have choose different if I knew that. I like to turn down the lights a little inside to conserve them. Suggested I could rewire on a different circuit, can't remember. Anyway, its the only thing flickering.

Post by **billofdurham** » 10 Jan 2010, 15:38

The battery's fine, but a little low on charge - 12.1V,

That is very low, but can be expected of a 5 year old battery. The manufacturers' figures are:
12.65 V 100% charge
12.45 V 75% charge
12.24 V 50% charge
12.06 V 25% charge
11.89 V 0% dead.

Bill.

Post by **jblackburn** » 10 Jan 2010, 16:33

Well, here's the latest one:
http://s105.photobucket.com/albums/m214 ... I_4911.flv
You can kinda see the pulsing better in this video, especially as the heater comes up.

Does anyone else's sound like that when you rev it? Maybe that is the alternator whining...I've always just accepted it as how the car sounded. The turbo whines a little bit in the cold, but that goes away once it gets going.

My battery has been drained several times from a door light switch that sometimes doesn't turn off, and was fully charged about a week and a half ago overnight from the same incident. It probably does need a new one, but I haven't had any issues in the coldest weather we've had, or slow cranking to this point.

Bill, I spent something like 6 hours driving last night - I would have thought that would be enough to completely recharge the battery to the levels you found there, but I was being pretty demanding on the electrical system. Heated seats, heater, radio, high beams, wipers, and rear defroster all going, along with the ABS constantly kicking in. It was cold!

I appreciate everyone's thoughts on this, I think I'm just kinda hoping that it's really something else, but it looks like it is the alternator

If I can figure out where my voltmeter went during the move, I want to test the voltage it's putting out at idle.

icelandic · Post by **icelandic** » 10 Jan 2010, 16:42

Perhaps your voltage regulator which integrates the graphite brushes is going bad or the brushes are worn. It is not very difficult to replace. If your alternator is not making any noises, indicating bad bearings it might be worth a shot.