Wiper/washer System GMC S15 Pickup

DESCRIPTION

There are two different systems available. The first is a permanent magnet positive park system with a dynamic brake and separate washer assembly. Washer system consists of a Permanent Magnet (PM) motor and pump assembly. It is mounted to solution jar by a nut located inside jar. The motor can be operated only when ignition switch is in "RUN" or "ACCESSORY" position.

The second, which is an optional motor, is a pulse mode. The components of the pulse mode are as follows

1. Multi-function switch.
2. Wiring harness from multi-function switch to wiper motor.
3. Wiper motor.

The difference between the two systems are that the pulse system uses an integrated circuit board to control the pulse function, and the multi-function switch has a variable resistor (rheostat) in the switch to control the rate of pulse to the wiper motor circuit board.

Wiper Inoperative

1. With ignition on, and wiper switch on "HIGH", ground 12-volt test lamp and touch probe to wiper terminal No. 1 (Lt. Blue wire). (Scheme 1) If light glows, proceed to step 3). If lamp does not light, check fuse.
2. If fuse is okay, repair open in feed circuit between fuse box and wiper motor. If fuse is blown, replace fuse. If fuse blows, check for short in wiring or high amperage draw in motor.
3. If lamp came on in step 1), place switch in "LOW". Connect jumper wire to ground. If wiper runs, repair open in ground strap. If wiper does not run, problem is in motor. Repair or replace motor as necessary.

Wiper Has Low Speed Only

1. With ignition on, and wiper switch in "HIGH" position, remove connector from wiper terminal. Connect 12-volt source to high speed terminal No. 1 (Lt. Blue wire). (Scheme 1) If wiper is inoperative, repair wiper motor.
2. With wiper in "HIGH", check for open wire from wiper terminal No. 1 (Lt. Blue wire) to column switch and repair. If wire is okay, replace column switch.

Wiper Has High Speed Only

1. With ignition on, and wiper switch in "LOW" position, remove connector from wiper terminal. Connect 12-volt source to terminal No. 2 (Black wire). (Scheme 1) If wiper does not run, repair wiper motor.
2. If wiper runs in "LOW", check for open in wire from wiper terminal No. 2 (Black wire) to column switch and repair. If wire is okay, replace column switch.

Wiper Works At Same Speed In Both "Low" And "High" Positions

1. With ignition on, and wiper switch in "LOW" or "HIGH" position, remove connector from wiper terminal. Connect 12-volt source to low or high terminals. If wiper runs at one speed, repair wiper motor. Check for shorting of low or high speed brushes.
2. If wiper runs in both "HIGH" and "LOW", check for open in wires from terminals No. 1 (Lt. Blue wire) and No. 2 (Black wire) to column switch and repair. (Scheme 1) If there are no opens, replace column switch.

Wipers Will Not Park

1. With ignition on, and wiper switch in "PARK" position, remove connector from wiper terminal. Connect jumper from terminal No. 2 to No. 3 and 12-volt source to terminal No. 4. (Scheme 1) If wiper is inoperative or does not park, repair wiper motor.
2. Check park switch actuator and brush holder. If wiper runs and parks in step 1), turn column switch off. Check current flow between terminal No. 2 (Black wire) and terminal No. 3 (Black wire with double Lt. Blue tracer) on harness. If lamp lights, check for open in wire from terminal No. 4 (Black wire with double Yellow tracer) to fuse block and repair.
3. If there is no current flow in step 2), check for open in wire from terminal No. 3 (Black wire with double Lt. Blue tracer) to column switch and repair. If there are no opens, replace column switch.

Wiper Will Not Shut Off

1. With ignition on and wiper switch off, remove connector from wiper terminal. Connect jumper from terminals No. 2 and No. 3 and 12 volts to terminal No. 4. (Scheme 1)
2. If wiper still runs, repair wiper motor (check park switch actuator and brush holder assembly). If wiper parks, replace column switch.

Intermittent Wiper Condition

1. Remove wiper fuse from fuse block and connect an ammeter across fuse block terminals. Operate wipers in "HIGH" with windshield dry. Current draw will fluctuate. If current draw is below 5 amps, a weak circuit is indicated. Replace brush holder assembly.
2. If current draw exceeds 5 amps, remove wiper arms, wiper blades and repeat test. If current still exceeds 5 amps, go to step 3). If current draw is okay, replace wiper blade elements and repeat test. If current draw is okay, problem is corrected.
3. If current draw exceeded 5 amps in step 2), disconnect wiper linkage from motor crank arm and repeat test. If current draw is okay, wiper transmission linkage is binding. Repair or replace as needed.
4. If current draw exceeds 5 amps with linkage disconnected, repair wiper motor. Check for shorted or grounded armature.

Wiper Motor Runs But Blades Do Not Move

Check wiper linkage connection to crank arm. If linkage is disconnected, connect linkage and check system. If linkage is connected, wiper gear is stripped. Repair motor.

Wiper Motor Parks But Above Normal Position

1. With ignition on, and wiper switch in "PARK" position, remove connector from wiper terminal. Check for open between terminal No. 3 and ground. (Scheme 1)
2. If there is an open, repair open in motor or replace holder assembly. If there is no open, check arm and blade location and/or transmission linkage.

Scheme 1

Wiper Motor Inoperative

1. Check to see if there is no power to the switch. To correct this check the fuse for the wiper and replace if necessary.
2. Check to see if there is no power to the wiper motor. Do testing under «SWITCH MODE TEST»(/gmc/s15-pickup/1987-1991/remont/wiperwasher-systems/#wiperwasher-system) below. If switch and harness fail test, check harness for shorts or opens. If harness is ok, replace switch.
3. Binding linkage or a broken wiper motor could also be a possible cause. To correct binding linkage, disconnect motor linkage, and retry the motor. To correct a broken wiper motor, check wiper motor using test procedure under «SWITCH MODE TEST»(/gmc/s15-pickup/1987-1991/remont/wiperwasher-systems/#wiperwasher-system) or J34660-A. If necessary repair or replace wiper motor.

Wiper Motor Will Not Shut Off

If wiper motor will not shut off, there could be an inoperative circuit board and/or inoperative park switch. If the circuit board is an inoperative, replace it. If the park switch is inoperative, check to see if it operates and replace if necessary.

Wiper Has High Speed And Delay

1. Check to see if there is improper voltage from the multi-function switch. Do testing under «SWITCH MODE TEST»(/gmc/s15-pickup/1987-1991/remont/wiperwasher-systems/#wiperwasher-system) below. If switch and harness fail test, check harness for shorts or opens. If harness is ok, replace switch.
2. Check to see if the circuit board is inoperative. If it is, replace it. Check to see if there is a broken wiper motor. To correct this, check the wiper motor using test using test procedure under «SWITCH MODE TEST»(/gmc/s15-pickup/1987-1991/remont/wiperwasher-systems/#wiperwasher-system) or J34660-A. If necessary repair or replace wiper motor.

Check to see if the circuit board is inoperative. If it is, replace it. Check to see if there is a broken wiper motor. To correct this, check wiper motor using test procedure under SWITCH MODE TEST or J34660-A. If necessary repair or replace wiper motor.

Wiper Operates In All Modes But Delay

Check to see if the circuit board is inoperative. If it is, replace it. Check to see if there is improper voltage from the multi-function switch. Do testing under SWITCH MODE TEST below. If switch and harness fail test, check harness for shorts or opens. If harness is ok, replace switch.

Wiper Does Not Delay Between Wipes

If wiper does not delay between wipes, check to see if the circuit board is inoperative, and if it is, replace.

Wiper Operates Intermittently

1. Check to see if there is a broken wiper motor. To correct this, check wiper motor using test procedure under «SWITCH MODE TEST»(/gmc/s15-pickup/1987-1991/remont/wiperwasher-systems/#wiperwasher-system) or J34660-A. If necessary repair or replace wiper motor.
2. Check to see if the circuit board is inoperative. If it is, replace it. Check gear train. If it is stripped, replace.

Switch Mode Test Schematic. Scheme 2

SWITCH MODE TEST

Removal

1. Disconnect battery negative cable. Remove wiper arms. Remove cowl vent and grille. Loosen but do not remove transmission drive link to motor crank arm attaching nuts.
2. Detach drive link from motor crank arm. Disconnect motor electrical leads. Remove motor attaching screws. Rotate motor upward and outward to remove.

Installation

Install motor by reversing removal procedure. Check operation of system.

Remove wiper motor. From housing side, drill ends off 7 rivets holding cover to housing with an 11/64" drill bit. Remove cover.

To install, attach cover to housing with self-tapping screws.

1. Remove wiper motor. Remove wiper motor cover. Remove crank gear lock nut, crank arm, shaft seal, thrust collar and washer. Push end of gear shaft through housing and remove gear assembly and washer.
2. File burr from retaining ring groove and where crank arm seats on shaft. Remove intermediate gear and washers. Drill ends off 4 rivets holding bearings and bearing straps in place with an 11/64" drill bit. Be careful not to get metal chips into motor.
3. Remove 6-point socket screws holding brush assembly in place. Remove armature, brush and magnet assembly together to avoid realignment of brushes.

To install, reverse removal procedure. Use new housing, retaining ring and self-tapping screws. Position thrust pin casing with insert about 1/32" above rear of pin.

WIRING DIAGRAMS

For wiring diagrams, refer to appropriate chassis wiring diagram in WIRING DIAGRAMS section.

See also:
• SWITCH MODE TEST