Windshield wiper only work on high

I did change the multifunction switch.. but did not help

I have this model so maybe I can help, Grand Marquis have a light box control under the dash and a wiper control also, some are SCR and relays that fail, this is a plug & play repair, however there can be a problem in the wiper switch itself, there's an air bag so I suggest a mechanic for this repair for safety reasons.

on my 2004 Grand Marquis, my wipers only work on the highest speed and do not retract. I changed the multifunction switch with a brand new multifunction switch, but the wipers still only work only in high speed, the turn signal part of the switch works, the high beam part of the switch works, the washer part of the switch works but the wipers do not come on for the usual 4, wipes and then should shut itself off and the wipers do not retract, even when the wipers only work on high, like they are doing. does anyone have any idea as to what is going on?