The linkages for the wipers are located under the dash pad, inside the vehicle.
Remove the glovebox. Drop out the glovebox light, disconnect the two wires to the light, remove the 4 or 5 grey plugs that retain the glovebox cardboard in the cavity. The plugs are two piece, so a thin bladed knife or a strong fingernail will do, lift the centre plug out first, then remove the locating plug it came out of. Replacement is reverse. You will then be able to see the linkage assembly and locate the problem. Hope that helps.