question on the main harness plug on firewall

use a small screwdriver, from drivers side fender, raise top of latch with screwdriver and lean top back on plug, then use your screwdriver on bottom of plug and press down on latch while pulling, it pulls a part easy, dont worry about getting them mixed up all 3 are made with a raised spot where they will only plug on 1 of 3 connections on the bulkhead. If you can get under dash ,there are 4 clips on bulkhead that you can release from outside at firewall, then you can pull bulkhead inside, under dash and inspect and clean connections