MTX Dodge Ram Quad Cab 2002-2003 Thunderform, Loaded with Dual 10 Inch Subs and Amplified, Charcoal Car Speaker "oil sending" Questions

where is the oil pressure sending unit on a dodge hemi motor? the truck is a 2003 See Image Below: next to the oil filter

...oil sending unit? it could be the oil pump getting weak. if the oil pressure is under 20 psi on the dash then it could be and be causing damage to internal parts. but if it goes away when it warms up ...