I bought this car in Dec 2020. 98 V70 2.5L AWD. It had sat for 3 years at an auto shop I take my cars too. They put a lot of work into it. And it runs great and hauls ***.

I just had to replace the turbocharger in it. Then battery is completely dead. I got a brand new one had it installed. Ever since then the immobilizer has not let me start it. There is no power to windows, door locks, seats, dashboard. Even the digital odometer and instrument cluster has no power. I've tried disconnecting the battery to reset computer... Nothing. I tried the key in the door locking and unlocking.... Nothing.

What do I do? I have only street parking and street cleaning is on Thursday.

Any advice is greatly appreciated.

 

Disconnect is not needed and won't do anything in a 1998.

Your immobilizer (alarm if you have one) prevents the starter from operating - nothing else. You should be able to remove the starter relay and use a jumper wire between terminals 30 and 87 - that will send 12v to the solenoid and the starter should work. If not your problem has nothing to do with the alarm. A common failure is the group of 4 wires that connects to the positive battery terminal to the fuse box under the hood.
They melt where connected in the fusebox, under the bolt with the 13mm head. Have replaced many as well as the positive cable that do to unseen corrosion inside the battery terminal (where it is clamped to the big red wire) current is prevented from starting or recharging the battery. Note the alternator (6/26 with the g in it for generator, and you don't have two, the dashed lines indicate two variants, diesel or gas) uses that same cable to charge the battery. (maybe your battery was not bad?) If you get it running do a voltage drop test on that positive battery cable - or just check the temp of the cable end - sometimes they get hot enough to burn your fingers.

On the diagram the ignition sw 3/1 sends 12v to the starter relay 2/35. The relay is grounded by 2/78 the alarm module. The relay closes and send 12v to 3/71 the neutral starting switch (if an automatic) - that goes to the starter solenoid on the starter 6/25 and ---------- the starter engages. A jumper wire in the correct slots where the relay plugs in and the starter will also engage without turning the key.
But if you have no power anywhere - I would invest in a $8 test light and make sure you have power at those fuses in the fusebox.

 

do the dash lights come on when you go to position 2? Wondering if you have a wonky ignition switch - try jiggling the key when trying to start.