dash lights go out when other circuits used

[weird beard]

1996 Volvo 850 wagon, 2.3 turbo. Just started doing this. I rolled the windows up and all the dash lights went out. they come back on when I stop using the windows. Adjusted the fan speed on the HVAC panel and they went out again. Cycled the key, they came back on until I loaded the window or fan circuit. I don't know what else is being affected by this yet. Car still runs, headlights still work. Display on radio still working, all back lighting flickering or going off completely. I don't believe the fan works when the lights go out. Sometimes they flicker, sometimes they dim, sometimes they go out completely. Like I said, it just started doing this, as I pulled up to the house and rolled up the windows.

[abscate]

Loose connector or perhaps bad grounds?

Are you an electrical novice, guru, or zen-master?

[weird beard]

I'm pretty good with the electrics. Spent years as the electrical "go to guy" at a Volvo TRUCKS dealer. However, I had full factory wiring diagrams, diagnostic tools and years of having seen similar issues on similar models. I will likely find it, thought I would post it up here to try and save myself some time. For alli know, this is a known issue with a known cause

[BEJinFbk]

I'm pretty good with the electrics. Spent years as the electrical "go to guy" at a Volvo TRUCKS dealer. However, I had full factory wiring diagrams, diagnostic tools and years of having seen similar issues on similar models. I will likely find it, thought I would post it up here to try and save myself some time. For alli know, this is a known issue with a known cause

Bypass the dash dimmer and see what you get.

[abscate]

We have an agreement with Volvo that we don't host electrical diagrams here but we can point tomthem for you. The headlight switched on these cars have a recall for some years and are a good starting point.