2020 Penta 240-V6-N motor changed oil n filter with volvo oil n filter 10-40 fully syn. now the oil pressure gage shows low pressure 1000rpm 12-12 psi 2000rpm 18-20 psi 3000 rpm 22-25 psi. usuyran between 40-60 lbs. thinking its the oil sending unit. but where is it? photo wiuld be great. thanks in advance