The solar flare is a large scale CME, they now call Coronal Mass Ejection. The issue with CME is that it stays on for a while, maybe a minute or two, turning long wires into heating elements. The telegraph wires of the day inadvertently acted as long antennas. The same event did little to damage equipment which was indoors or disconnected.

I don't want to get too deep into "what if the world ends" but there is certain stuff that you can't defend against without a serious underground bunker.

Your EMP wave from a weaponized EMP device is short term. It is also not exactly linear. More like a fast moving cloud or zone of radiation. It can actually seep through cracks in shielding. For example, a high power EMP can apparently get into an ammo can or trash can which does not have conductive metal tape around the lid gap. Wires leading into and out of a shielded computer can carry the shockwave, but the shielding still reduces damage.

The effects on cars they are finding are often just temporary. The police model EMP guns for example knock out the vehicle but quite often it can be restarted. You may be able to find a matching vehicle computer in a box or wrecked vehicle of similar type which was not running at the time of the EMP and use it to repair one which was damaged. Multiple EMP hits may accelerate wear and faliure on electronic devices which got hit but temporarily recovered.

We don't know much about how CME would affect power wiring in buildings, because that was just not around much in the 1800s, but in theory, it could cause fires. EMP, just too short term to be an issue.