I was driving our 98 Subaru Outback when I first drove I noticed the rpm and speedometer needles were  going crazy. We entered the high way and the car started to run very rough, At this point the radio died, the RPM and speedometer stopped working, as well as the air conditioner. Before we could pull over the car was not long getting gas and the motor cut off. Once we were pulled over the car was very sluggish to start at first, would run for a few minutes before everything would start to give out and not work. After about three attempts to start the car it would no longer turn over. Just the starter clicking, The dealership ( FORD) we broke down in front of  told me it was an electrical issue and would be very expensive. I called a Subaru dealership and they said alternator, I can do the alternator myself. I just need some thoughts.

Probably the alternator. Charge the battery and have the charging system tested (most parts stores can do both).

That alternator can be bought remanufactured from Subaru for about $75.

Either battery or alternator is bad. Neither are expensive. If it were me, I would get the car home. Then, recharge the battery, also checking to see if the battery is full of water. Once charged up, you should be able to start the car, and If the dash needles still go crazy, then I would suspect a dead cell in the battery. I had that happen in a VW years back with crazy guage readings. If you can limp the car into an auto parts store, they will come out to the parking lot and test your charging system for free. Then, you will know for sure if it is battery or alternator. Also, recently my daughter reported her BMW developed crazy dashboard readings. She replaced the battery, and all was fixed. If your battery is old, then maybe best to replace the battery, or at least remove the battery, take to a car parts store, where they will test the battery at no charge to see if it is good or bad.

 

 

 

Btw, did you have any warning lights come on at the dashboard?