No dash or instrument lights

[Magnetoresistive]

I'm currently borrowing a 2000 Pontiac Grand Prix GT, and in exchange, I'm trying to fix some of the problems that have popped up over the last 13 years. One of these is that almost none of the instrument lights work, and haven't for a long while. Recently, however, on a very cold night, they all came back for just a few minutes, and this has led me to believe the problem might be fixable, if I can get some more information about it.

 

Right now, when you turn the headlight switch on - or when the car turns on the headlights because it's dark - the following lights do not come on: dash, door controls, steering wheel controls, heater controls, HUD position and brightness controls. Basically, anything that's supposed to light up, doesn't. [The gas computer display does light up, as does the HUD.] The heater control screen - it has the dual-zone climate control version - turns off when the headlights are on, but if you rock the headlight switch back and forth, it'll turn on briefly.

 

Is this a known issue, a common problem? I tried the Search, to no avail. If not, any suggestions on what to check, where to look? A bad ground seems like the simplest explanation, but I'm not that familiar with W-bodies, and not sure where to even start looking for said ground.

 

Thanks!

[l67ss]

Id try another headlight switch. Hit me with another prob, im feeling cocky

I'm currently borrowing a 2000 Pontiac Grand Prix GT, and in exchange, I'm trying to fix some of the problems that have popped up over the last 13 years. One of these is that almost none of the instrument lights work, and haven't for a long while. Recently, however, on a very cold night, they all came back for just a few minutes, and this has led me to believe the problem might be fixable, if I can get some more information about it.

 

Right now, when you turn the headlight switch on - or when the car turns on the headlights because it's dark - the following lights do not come on: dash, door controls, steering wheel controls, heater controls, HUD position and brightness controls. Basically, anything that's supposed to light up, doesn't. [The gas computer display does light up, as does the HUD.] The heater control screen - it has the dual-zone climate control version - turns off when the headlights are on, but if you rock the headlight switch back and forth, it'll turn on briefly.

 

Is this a known issue, a common problem? I tried the Search, to no avail. If not, any suggestions on what to check, where to look? A bad ground seems like the simplest explanation, but I'm not that familiar with W-bodies, and not sure where to even start looking for said ground.

 

Thanks!

[Imp558]

Dimmer knob! Bypass it and see if they come on full bright

[RobertISaar]

headlamp switch in general seems to be fairly common. mine did something similar for a while; randomly during a drive, the entire cluster backlighting would shut off. sometimes, moving the switch from off to headlamp would make them come on again, but not reliably.

 

i took it apart and didn't find any obvious issues, so i modified mine a bit.... i connected the dimmable portion of the circuit directly to the headlamp feed, so now the cluster is at full brightness whenever the headlamps are on.

 

an interesting side-effect that i didn't account for was that now when the headlamp switch is in the park position, i can vary headlamp intensity with the interior dimmer switch.... operating like that for very long will probably damage the switch to the point of failure though, so it is avoided.

[Imp558]

That's funny, Maybe jump that bad boy with a diode. Too bad the dimmer isn't seperate like the Buick, probably more expensive to buy the switch/dimmer combo.

[RobertISaar]

That's funny, Maybe jump that bad boy with a diode.

 

if it bothered me, that would be the route i would go. i have ~20 1N4007 sitting around, the ~.7 volt drop from them wouldn't even be noticable, would have to check current draw to see how many would be needed.

 

but...... car hasn't been driven since october of last year.... so not much of a priority.

[Magnetoresistive]

Awesome, thanks! I've wanted to replace the headlight switch anyway, to try to fix the weird climate control display issue, but I'd only looked at "new" pricing, and that's a couple hundred bucks, depending on where you get it. But I checked used ones yesterday - with guarantees! - and found them in the $20-$40 range, which is more than reasonable. I'll give it a shot ASAP, and let you all know how it goes!