Ok i got the jdm h22a in finally but i got this wierd idleling problem when im just sitting there idle/at a stop/etc

it will rev up from 1000-1800 rpms

BUT it only does this when my headlights or my heater is on
the shop i took it to get the work done says its a short in the harness

some people say its my o2 sensor some say its my iavc some say this and that

ive turned the iavc screw (the one on the TB) all the way to the right and it still hasnt stopped the problem

there are no vacuum leaks (that i know of ) that i know

was wondering if any of you had any idea how i can fix this