96 Geo Tracker loses power on highway

Hello, my daughter (18) has a GEO tracker which has been losing power while driving. She will lose all lights, radio and power and has been stranded in the middle of the road more than once. Jump starting always worked and she would be able to get back home. So we had the alternator replaced. It helped but the battery still wouldn't keep a charge. Then we replaced the battery. The car drove well for 2 days then when my daughter was in Washington DC at school, the car died again in the middle of the road and the police had to call a tow truck.

She says that the front dayrunning lights are blinking, there is a warning light on the dash (she says it is a light with 3 lines) that is blinking, the battery light is on and the inside of the car is beeping along with the headlights blinking.

Could we have an immobilizing car alarm? I know that about 8 years ago I did cut the wires to an alarm horn, but we bought the car used in 92 and I don't know its history.

Could all this be because we changed out the battery?

Please help, all suggestions are welcome. We can't afford another trip to the mechanic.

Thanks.
Alana

Could be an alarm, but if it were you probably would have noticed this behavior immediately. More likely an electrical problem, bad connection, etc., which leaves the battery offline. Check the negative cable attachment to the block or frame. Also check the ground to engine strip. These guys draw a good bit of power, so while they may run with minimal battery, they don't run well, and that means a lot of surging as electrical demands fluctuate, which might seem like an alarm - sort of. Check the relays, and fuses. Check voltage across the battery when the vehicle is running. Should be above 12 volts. Engine space these vehicles is limited so bench testing the alternator is advised. You don't want to lose an arm fiddling with any car. Also have the alternator checked, even new ones are sometimes bad, and rebuilds are often problematic. I would guess you will need professional help with this - a mechanic with significant motor vehicle electrical system experience. The Haynes manuel has the circuit diagrams and layouts.