In the 2000 Alero, it is fuse 34 in the engine fuse box, which is located near the battery. You can check the same fuse for the 1999 Alero and see if that is it.
check engine light
If your Oldsmobile Alero will not shift into overdrive, the transmission may have froze up. Check the fluid levels to determine if you are low on fluid.
Have the problem repaired and they will reset the light. If you DIY then disconnect the negative battery cable for 5 minutes. If that does not reset the light you will have to have it reset with an OBD2 scan tool.
You can find sliders for a window regulator on an Oldsmobile Alero at most auto parts stores. Another option, is to check with local junk yards.
take the battery cable off for 15 minutes
Check fuse nr 34 under hood!
there are two things to do first you can reset the computer by disconnecting the battery for about 1/2 hour then if your light still comes on after that just go to an autozone and they will check the light out for you for free and let you know what needs to be fixed and what code you have.
You can disconnect the negative battery cable, wait a couple minutes then reconnect the cable. This will clear the codes and reset the check engine light but, if the reason the light came on isn't fixed the light will come back on soon.
Check
Check the brake pedal switch. Check the bulbs. Check the grounds.
there is no dipstick for the transmission on an alero there is a fill spot crammed on the transmission beside the motor to check it you get under and pull out a plug on the tranny