Cannot tell you about the pucker factor when installing a hew harness, with ignition switch, where OEM was having problems, and turn signal switch. The light switch seemed OK. So, remove the old harness, a mess, for sure. Then, lay out the new harness on the floor and try to negotiate what needs to be done. The PL harness has been good so far. So, place the new one in the dash, and try to find a place for the new fuse panel, that must be able to be accessed easily. Pull the engine and headlight harness thru the dash....I used the existing bulkhead fitting for a new hole. So, began with Ign switch, then light switch, and wiper switch. Then focus on the wires in the engine bay for starter relay, alternator, coil, and sensors, incl new OP pressure gauge. So, now need to test the harness using a 10-15 amp fuse for power, and turn on switch, check those things that should have ign power. Then, turn on light switch and check both front and rear lights (harness output). Also, in the mix, is to power up the OEM harness for both front and rear lights to see if the existing harness works, to use it for now. Lights all work...or mostly. Harness OK for now. So, after checking the harness by turning on the ign switch, then light switch and looking for output at the harness, found a couple problems that had to be attended to. So, next was new turn signal and horn relay, with output at the rear turn signal and brake lights. So far so good...after a month of work, I am a happy camper.