Peculiar Problem With Dashboard Backlighting -- Theories?

My dashboard backlighting has been blinking on an off intermittently. Before you freak out, there is also direct lighting that is not affected, so I can still see the speedometer etc, just not quite as well.

Here’s why its odd. To me anyway.

Typically, if I get into my car at night, and switch on the headlights/backlighting, the backlighting does not immediately turn on. The headlights work normally although the same switch turns both the headlights and the backlighting on. After a few minutes of driving, it will blink on, sometimes blinking off one or more times over a period of 10 minutes or so, before finally deciding to stay turned on. It is NOT affected by jostling, ungraded road, sudden turns or other things that I associate with loose connections. I drive over some pretty hard bumps and badly graded bridges on my drive home from school, so this has been amply tested.

I just got a new battery, so that’s not it. The problem preceded the low battery, and was not fixed by the new one.

The only thing that does seem to affect it, is the temperature in the passenger compartment. If I blast the heat in the passenger compartment, it will blink on sooner and stay on with fewer “temporary blinkouts.”

What the hey? Any theories? I hate going into a repair shop without having at least a ballpark notion of what might be wrong.

I used to have an Accord, the wipers on which wouldn’t turn on for a while after the engine was started. I imagine you have a loose fuse or relay or something and when the engine gets hot enough it swells to fit whatever gap or hole it is sitting in.

Sounds like a dirty/oxidized connection. I’ve seen this kind of thing with (cheap) boomboxes. One speaker will be intermittent, but if I blast it (up the volume) the speaker will make a good connection. Unfortunately you may not have the option to do this with your dashboard lights (do you have one of those controls where you can dim the dashboard lights ?).

There is likely one of those plastic cable connectors inside which the pins have started to make iffy contact. Unfortunately it is probably a bitch to get to. But you’d probably only need to unplug, clean the pins, and re-plug to fix it.

The first thing to check on intermittent electric devices in a car is the ground.

I would agree with that.

Have you tried adjusting the brightness of the backlighting? I have an old car where the backlighting works just fine, as long as you don’t touch the dimmer. Once you do, it goes on and off intermittently until you adjust the knob to just the right spot again, then it stays on. My car, I think it’s simply worn or dirty contacts in the dimmer.

I had a television with similar problems with the sound. When I first turned on the tv there would be no sound. After about 5 minutes there would be intermittant screeching and sound and then it would finally settle in and work fine.

When I took it in for service they told me there was a broken solder joint and as it heated up and the metal expanded to make the connection the sound would come back.

Still a bitch to track down, especially in a cramped setup behind the dash.

What kind of car is it? The only reason I ask is because I’ve been having the exact same problem with my Hyundai Accent. Seems like it started after I had it in to the dealer for some brake work and a routine inspection. Most of your symptoms seem pretty much the same (not caused by bumps, turns, ect), but mine actually seems to be less fussy they colder it is out.

A couple people mentioned checking the grounding–how would we do that?

Hyundai Accent. 02. Huh.

To the poster who asked, I don’t think the backlighting has a dimmer, or, if it does, I’ve never touched it in the past 2 years.

It’s to the left of your steering wheel, duckie :stuck_out_tongue:

(It’s a wheel - sort of like a mouse scroll wheel… you move it down to dim, up to brighten)

Google suggest that intermittent dashboard lighting is a fairly common problem on the '02-'03 Accent, and it appears that loose or messy fuses are the culprit.

Fuses ? The little doohickeys you by for $5 at the autoparts store or Special Fancy Experts-Only fuses?

The regular kind in a little unclippable black box.

I didn’t know there were fancy experts-only fuses.

In the eons since alternators replaced DC generators, I’ve had a handful of alternator failures. As often as not, the first symptom was the dashboard going weird. It seems like such a harmless little quirk. I seem to forget every time that alternators all belong to the religion that believes in dying on weekends after the repair shops have closed, as far from civilization as possible. I don’t know how an alternator can get all that information, but maybe it proves the validity of their odd, aluminum-clad religion. :dubious:

Funny, mine’s an 02 as well. I first suspected a fuse but a quick inspection didn’t turn up anything obvious. I guess maybe I’ll take a closer look this weekend.

If you don’t know about it already, there’s a pretty good Hyundai owners forum here:

It includes info on how to access shop manuals online, which I’ve found to be pretty useful.

Hmmm. I’ve also got an '02 Hyundai Accent that’s had the same problem for several months now. Every so often the dashboard backlight will turn on or off. It’s not related to potholes, bumps, or temperatures, or any other triggers that I’ve been able to find. I’ve been meaning to take it to the dealership to see if they can do anything about it, but I keep wondering if it’s worth the cost.