A/C - No Low/Medium Blower Speed

88chevy07
Number: 88-183-1A

Section: 1A

Date: APRIL, 1988
Subject: NO LOW AND/OR MEDIUM A/C-HEATER BLOWER SPEED


Model and Year: 1988 C/K MODELS WITH A/C (RPO C60)
TO: ALL CHEVROLET DEALERS


A loose evaporator screen or loose wire in the screen may contact and short the low and medium speed resistor in the A/C-heater module on some subject vehicles. This could result in a lack of low or medium blower motor speeds.

To repair this condition:

1. Disconnect negative battery cable.
2. Remove glove box from dash.
3. Remove the two screws securing bracket bar to heater module and set bracket bar aside.
4. Remove resistor (See Service Manual ST-375-88, Page 1B-27 for illustration of resistor) located on top of heater module.
5. Check for loose evaporator screen wire which may contact resistor. Remove if present.
6. Glue or epoxy the loose screen to the top of the evaporator core. Hold the screen against the core and liberally apply DAP Contact Cement or equivalent along top of screen or press RTV through screen to top of core.
7. Replace resistor, Part Number 15551633.
8. Reinstall bracket bar and glove box and reconnect negative battery cable.
Screens have been secured to the evaporator coil by means of a plastic prong retainer in production starting with the following VIN breakpoints:

Assembly Plant VIN Breakpoints

Pontiac JE145735
Fort Wayne JZ157778
Oshawa J1180739

For repairs to vehicles under warranty use:

Labor Op.: D1002
Time: .5 hrs