2005 4Runner two wheel drive only blows cold AC on the right side, on the left side it blows warm. How do I fix this?
@Chucktobias likely already pinpointed this issue.
I will say that my 2008 GX470 with likely the same system did this to me, all I had to do was get a good shop to do an AC service, drain it and fill it up and check for leaks. No leaks detected and it has run for 2 years with no issue. After enough usage they lose some and do exactly what yours is doing, runs some on passenger side.
That or the blend door.
The most likely issues are either you have faulty control flaps in the dashboard or are low on refrigerant.