Checking the trans fluid is a pain.

It can be done cold but it is more accurate to check it hot. Run time depends on your ambient temperature. Ten minutes ain't going to do it at 0F. Hot or cold, Start the car and cycle through all lever positions, leaving it in each spot for 2-3 seconds. Check the fluid idling in park.

The easiest way to access the dipstick is from below. Remove the splash shield. Wedge a small screwdriver handle in the latch clip to keep it out of the way. Since the fluid has not been checked in 15 years, turn the dipstick to get the o-ring freed up before you try to pull it out.

It needs Volvo spec ATF, not run of the mill Dexron. I use Valvoline Maxlife synthetic AFT, VV3246. I'm sure there are other brands that meets Volvo's specs too.
Greg