Hmm strange .. maybe cuz mines a Canadian car , my low pressure port is located under the pressure switch that is on the top of the drier. It took a bit to find it, unscrewing the switch was almost a last resort! It`s all good now, 34 degree drop at the vents on max A/c ( I do tho, have a coupler at the location that was given to me, maybe the 89`s are different ? )