Buick Repair Questions? Ask a Mechanic for Answers ASAP
Can you feel if both heater hoses/pipes to the rear heater core are hot after the engine has warmed up?
I'll look it up but first make sure the engine coolant level is full.
You may have to jack it up, then remove the right rear wheelhouse liner panel.
Here are the instructions for accessing it plus a diagram,
The rear heater hose/pipes are the 2 and 3 in the diagram.
You have to maybe remove the wheel, if those hoses are not exposed somewhere under there,