Heat in 1999 Astro Van

tsb # 01-01-38-003

Poor Heat Distribution in Driver's Area of Vehicle (Install New Heat
Diverter Ducts)
1996-2001 Chevrolet and GMC M/L-Van Models

Built Prior to the following VIN Breakpoints:

Make
VIN Breakpoint

Chevrolet
1B111821

GMC
1B504468

This condition may be corrected by installing a newly designed center
heat duct and diverter tube. Use the following procedure and the part
numbers listed below to install the new ductwork.

Remove the screw covers from the top of the instrument panel (IP)
extension and remove the retaining screws.
Remove the retaining nuts from the bottom of the IP extension.
Remove the IP extension from under the IP by pulling the extension
outward and disconnecting the electrical connector.
Remove the screws (total of 3) that retain the driver's knee bolster
to the IP.
Disconnect the park brake release cable from the park brake assembly
and remove the knee bolster from the vehicle.
Place the knee bolster on a clean, flat surface with the colored side
up. The knee bolster will be resting on the lower edge tabs on the
bench. The right side tab is where the tube must be attached.
Lift the knee bolster and place the mounting of the flexible heat duct
on the right side mounting tab of the knee bolster. Mark and drill two
5 mm (13/64 in) holes in the knee bolster mounting flange.
Attach the mounting flange to the knee bolster with the screws.
Tighten
Tighten the screws to 2 N??m (18 lb in).

On panel vans, it will be necessary to remove the duct attaching
screws from the floor of the vehicle.
Remove the original center heat duct from the vehicle by grabbing at
the top left corner of the duct and then pulling the duct to the left
and out of the vehicle.
Position the new heat duct to the floor outlet, if equipped, and snap
into the heater case.
On panel vans, reinstall the retainers for the heat duct into the
floor of the vehicle. Tighten
Tighten the retaining nuts to 2 N??m (18 lbN??min).

Reinstall the knee bolster to the vehicle. Position the new heat duct
into the opening of the IP support brace and onto the outlet from the
center heat duct.
Reconnect the park release cable to the park brake assembly and
install the three knee bolster retaining screws.
Reposition the IP extension to the IP and reconnect the electrical
connector.
Install the retainers. Tighten
Tighten to the retainers to 8 N??m (71 lbN??min).

Install the screw covers to the IP extension
15754078
Duct Asm - Flr Air Outlet
1 per vehicle

15754076
Outlet, Flr Air (Passenger Vans)
1 per vehicle*

15754077
Outlet, Flr Air (Panel Vans)
1 per vehicle**

9423101
Screw, Tap
2 screws required per vehicle

hope thats what you were looking for

Brian