Shrouds make all the difference in how a vehicle cooling system performs. Take it to the extreme, look at F1 and NASCAR’s… any deviation in the panels changes the speed of the vehicle. Cars lose a couple of mph easily from just missing bumper pieces. Air is effected the same on your vehicle.
Perfect example. F150 was running hot. Customer ‘diagnosed’ the faulty fan clutch and replaced it. Now the vehicle cools fine… except the A/C short cycles. Before dropping $500+ for a compressor, drier, oil, etc (future posts to come on why you replace the critical stuff together) he brings it to me.
Gauges show the high side spiking well over 350psi causing the cutoff switch to short cycle the A/C clutch. Customer swears he followed the under-hood sticker for the quantity. I then notice some plastic missing on the top edge of the shroud. He fessed up that it broke off during the fan clutch install. I told him that he needed a new shroud. He called BS. So I bet him $50 and a case of beer. I slapped on a piece of duct tape and tested my theory.
Let’s just say that beer was ever sweeter than normal.