1986-91 ACCESSORIES/SAFETY EQUIPMENT

1986-91 ACCESSORIES/SAFETY EQUIPMENT
Steering Column Switches
DESCRIPTION

WARNING: All models are equipped with Supplemental Restraint System (SRS). Observe SERVICE PRECAUTIONS before performing ANY repair. Failure to follow air bag precautions may result in air bag deployment and personal injury. See SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAGS article in the ACCESSORIES/SAFETY EQUIPMENT section.

NOTE: Information for 190E models is not available from manufacturer. See Fig. 1 .

The combination switch contains dimmer switch, turn signals, and windshield wiper controls. Headlights and hazard flasher switches are mounted in instrument panel.
TESTING
ADJUSTABLE STEERING COLUMN

NOTE: Information is not available from manufacturer.
COMBINATION SWITCH TEST

Remove lower instrument panel cover below steering wheel. Locate and unplug combination switch 13-terminal connector that is mounted to instrument panel brace, left of steering column. See appropriate COMBINATION SWITCH CONNECTOR TERMINAL IDENTIFICATION .
COMBINATION SWITCH CONNECTOR TERMINAL IDENTIFICATION

COMBINATION SWITCH CONNECTOR ID (300 SERIES)
Terminal Wire Color Function
1 White/Yellow Dimmer Switch Voltage
2 White High Beam Flash/Passing
3 Yellow Low Beam
4 Black Horn Voltage
5 Black/Pink/Red To Horns
6 Black/White Left Turn Signal
7 Black/Gray/White (1) Voltage From Flasher
8 Black/Green Right Turn Signal
9 Black/Brown (1) Intermittent Wiper Voltage To Combination Relay
10 Purple/Yellow Windshield Washer
11 Black/Yellow Ignition Voltage Input
12 Black/Yellow/Gray Wiper Low Speed
13 Black/Yellow/White Wiper High Speed
(1) Flasher is a part of combination relay. Combination relay combines functions for turn signal flasher, heated rear window timer, and intermittent wiper into one relay.

COMBINATION SWITCH CONNECTOR ID (350 SERIES, 420SEL & 560 SERIES)
Terminal Wire Color Function
1 White/Yellow Dimmer Switch Voltage From Terminal No. 56 Of Light Switch
2 White High Beam Flash
3 Yellow Low Beam
4 Black/Purple Horn Voltage From Fuse Block
5 Black/Pink/Purple To Horns
6 Black/White Left Turn Signal
7 Black/Gray/White (1) Voltage From Flasher
8 Black/Green Right Turn Signal
9 Black/Brown/Yellow (1) Intermittent Wiper Voltage To Combination Relay
10 Gray (1) To Windshield Washer Pump & To Combination Relay
11 Black/Yellow Ignition Voltage Input
12 Black Wiper Low Speed
13 Blue Wiper High Speed
(1) Flasher is a part of combination relay. Combination relay combines functions for turn signal flasher, heated rear window timer, and intermittent wiper into one relay.
HORN TEST

1. Remove lower instrument panel cover below steering wheel. Locate and unplug combination switch 13-terminal connector that is mounted to instrument panel, left of steering column. Locate horn terminal No. 5 on connector mounted to panel. For wire color of terminal No. 5, see applicable COMBINATION SWITCH CONNECTOR TERMINAL IDENTIFICATION .
2. Using jumper wire, connect terminal No. 5 to battery voltage. Horns should sound. If not check wiring circuit from terminal No. 5 to horns. Repair wiring as required or replace horns.
3. At combination switch side of 13-terminal connector, connect ohmmeter to terminals No. 4 and No. 5. For wire colors of terminals No. 4 and 5, see applicable COMBINATION SWITCH CONNECTOR TERMINAL IDENTIFICATION .
4. Depress horn pad on steering wheel and note ohmmeter reading. If continuity does not exist, remove air bag module and check horn wiring. See AIR BAG MODULE & STEERING WHEEL under REMOVAL & INSTALLATION.
5. If horn wiring and connections are okay, remove steering wheel and check slip ring, carbon contacts and related wiring to connector. See AIR BAG MODULE & STEERING WHEEL under REMOVAL & INSTALLATION. Repair as required or replace combination switch.

IGNITION SWITCH TEST

Remove ignition switch. See IGNITION SWITCH & STEERING LOCK HOUSING under REMOVAL & INSTALLATION. See IGNITION SWITCH CONNECTOR TERMINAL IDENTIFICATION .

IGNITION SWITCH CONNECTOR TERMINAL IDENTIFICATION
Terminal Wire Color Function
P Green/White To Headlight Switch
30 Red Battery Voltage
15R Pink/Yellow Accessories & Fuse Block
15 Red/Black Or Red/Pink Ignition System & Control Unit
15X Red/Green Electronic Blower Control
50 Purple Ignition System & Starter
WIPER SWITCH TEST

For testing information on wipers, see appropriate WIPER/WASHER SYSTEMS article.
REMOVAL & INSTALLATION
AIR BAG MODULE & STEERING WHEEL

1. Before proceeding, follow air bag precautions and disable SRS. See SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAGS article.
2. Remove steering wheel air bag module by using long shank Torx TX30 bit to remove 2 Torx screws from rear of steering wheel. Lift off air bag module enough to unplug connector from rear of module. Place module away from work area, with pad facing upward. Disconnect horn wiring.
3. Ensure front wheels are in straight-ahead position. Remove steering wheel hub bolt. Reference mark steering wheel-to-shaft position. Pull steering wheel off with hands, or if necessary, use proper steering wheel puller to remove steering wheel.

CAUTION: When removing steering wheel, use extreme care not to break carbon contacts mounted to top of steering column.
Installation

NOTE: DO NOT lube slip ring contact surfaces on steering wheel.
Position steering wheel onto shaft splines, aligning reference marks made during removal and aligning turn signal restoring cam on steering shaft with combination switch tang. Install steering wheel to column using caution to ensure contact carbons are not broken.
2. Install a NEW hub bolt and tighten to 60 ft. lbs. (80 N.m). To install air bag module, reverse removal procedure. Connect horn wiring. Tighten Torx screws to 53 INCH lbs. (6 N.m).
3. Activate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAGS article. Perform system operation check to ensure system is functioning properly. See SYSTEM OPERATION CHECK in appropriate AIR BAG RESTRAINT SYSTEM article.

COMBINATION SWITCH