Subaru Forester, 2003. clock light and dome light not working (clock works, just no light at night). all other dash lights appear to function. i replaced fuse marked 12 in engine fuse panel, described in Owner's Manual as "clock, interior light". it seems to have reset clock (time), and trip odometer, but still no lights on the clock or dome.

First, check the following. I believe the 2001 Forester had a 3 position dome light switch. One position turned it on, one turned it off, and the third position enabled the light to come on when a door opened. Not all years had this type of switch. If yours does, check whether the light comes on for each and every door one at a time. If it fails for a particular door, you have narrowed the problem.

If this problem always existed for your Forester, possibly the assembly was not properly done. If it is a new event and the dome light switch is in the proper position, there may be a short in the wiring. You would have to test the wiring with a multimeter. Perhaps this service manual will assist: https://servicingmanuals.com/manual/2001-subaru-forester-wiring-diagram/

https://fuse-box.info/subaru/subaru-forester-sg-2003-2008-fuses
03 and 05 have fuse in different place not sure which one applies to you. Above is 03 and 05 fuse box diagram.
The dome light comes on when you open car door. I have had cars where the door switch was bad and would not turn light on. If your dome light has a switch on the dome light then you should have power to switch. If not and the fuses are good then it seems it would have to be a problem with wires or switches.

Fuses under the dash.

if the car stop or battery discharged when the dash light went out then it maybe alternator belt or alternator is the problem

Is this for a 1999 Forester or for a 2004 forester, the title lists both years. If it is a 1999 model then the problem most likely resides within the clock itself. Unfortunately, many clocks of this vintage go bad over time. I offer a reasonable repair service and many clock removal instruction sheets at www.autoclockrepair.com
I'd be happy to assist.

Sounds like your clock is dying. This is typically an issue with the clock itself. This is very common with many vehicles, CR-Vs, Pathfinders, 4runners, etc. The good news is that it can be repaired for a reasonable rate, check out www.autoclockrepair.com

Did you check the underhood fuse #30, 15amp which controls illumination and the clock? It appears as though there are 2 fuses which control the clock, one under hood and one in the cabin (#9).

Take a look at your dome like switch to see if it can dim the overhead light any.If it can't, I would start there. If that checks out, then check all connecters going to the instrument panel to see if any of them are loose.

just follow the wires that cnnect to the speedometer light and screw to change bulb . thesame as to the tachnometer light there also is awire connected to it .

Go to www.subaruforester,org and do a search for clock. This is a chronic problem but if you're handy with a soldering gun you can fix it yourself.