Hey everyone,
I am having a massive headache with a local shop over my 1999 Ranger 4.0L V6 AC system and really need some community input and pictures.
Originally, my AC wasn't holding pressure. The shop diagnosed it and replaced the evaporator core and the plastic HVAC box. I didn't notice it right away when I picked the truck up, but they completely left off the factory silver foil heat shield blanket—they just threw it out with the old box and left the new aftermarket box as 100% bare black plastic.
Since that repair, the AC works great while I’m moving/driving fast, but the second I sit at a red light or get stuck in traffic, the vents start blowing warm air.
I brought it back to the shop because of this idle issue. They kept diagnosing it and have now replaced both the compressor and the condenser coil, yet the issue remains exactly the same: cold while driving, warm at idle and in traffic.
Now they are guessing it might be a "drain orifice" or a "dryer box," but I strongly suspect the bare plastic box is just getting completely heat-soaked by the passenger-side exhaust manifold when there’s no highway airflow to cool the engine bay down.
Has anyone else experienced this? Is losing that factory heat shield the exact reason it’s failing at idle?
Could anyone with a 1998–2000 4.0L Ranger drop a clear picture of their engine bay showing that silver factory insulation wrapper (Ford Part # XL5Z-19B666-AA) on the passenger firewall? I need solid proof to show the shop manager that this part exists, is necessary, and needs to be replaced with a universal aluminized heat barrier on their dime.
Thanks in advance!