The dimmer switch could be culprit. My dimmer wheel had a short in it on my SVT and it made the gauge lights flicker. I had to replace the whole headlight switch.

 

Do this. I had the same problem, and got a new headlight switch. All problems solved.

 

be careful, usually if the dash lights are out the tail lights are out too. Mine was some stupid passive security system someone had installed.

 

My tail lights seem fine, side marker lights are out as well,thought I'd check the bulbs on these two front side ones and also the dimmer switch and go from there.

 

Ok new bulbs in the side marker lights did the trick. Now just need a solution for the instrument(dashboard) lights, pulled out the headlight switch and all seems fine but probably wouldn't know unless I changed this out if it is the culprit to the dashboard lights not working.

 

You might try the interiors forum

 

I am also having a problem with my gauge lights, I replaced the switch and still have the same problem.

When I first turn on the head lights the radio, needle and other lights come up right away but the gauge (electroluminescent) lights slowly come on and are usually kinda dim (dimmer is at full brightness) then after ~30 minutes of driving the gauge will turn off again.

The dimmer switch works fine to dim the radio lights, needle lights etc.

Any ideas?

Edit: found this post as a possible solution http://forums.focaljet.com/interior-modifications/616768-svt-guages.html

Any other ideas?

 

my dash lights will come on sometimes for 30 mins some times they will be out by the time i back out of the drive way...it also turns out the AC/Heater controls and the radio controls.

 

I have a 2003 ford focus svt zx5 dimmer switches, turned all the way up the needles light up on all the gauges and so does the digital part the lights on the air conditioning and heat controls whole lot up and when turning them or switch down, they dim down like they’re supposed to my problem is the back light on my cluster will not illuminate what could be coughing

 

The inverter for the gauges probably is bad:

https://www.focaljet.com/threads/focus-svt-electroluminescence-dash-light-fix.671431/