SCE registration

yes bro there will be conflict from jawasat, esp when your on job site and they check your iqama written on a different position, there will be no questioned but to cut your iqama on the spot (not to scare you just base on my experience, not to me) and there will be no quarrels from both side. As far as i know they stop giving this kind of position because they are prioritizing saudi not unless your new in ksa. goodluck then......

i work here in saudi for 1 year now in a manufacturing company, i need to register now coz my iqama will be expiring this month.

Yes, there will be conflict. I guess this is a move by the government to ensure that you work according to your field of expertise, like Physicians and other licensed Medical Professionals do. They do this in the UAE, and part of the licensure process is the verification of education, home country license registration and good standing, and of course previous employment/s.

what will i do now, do i need to change my visa to electrical engineer

You have to apply for change of profession. You have to do this with the authenticated suuporting papers for that profession.