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-   -   Information: Headlamp Wiper Motor Repair (https://www.volvoforums.org.uk/showthread.php?t=51146)

Jod T5 Jan 13th, 2008 20:42

Headlamp Wiper Motor Repair
 
Have you ever been embarrassed with an erect headlamp wiper....
http://i35.photobucket.com/albums/d1...r/IMGP1449.jpg
There is an easy but fiddly solution to the problem...
First of all we need to understand how the motor works, there are two positive inputs and one negative...The negative is permanent as is one of the positives, the main circuit being interrupted only by the leaf contact sensor ...The leaf contact sensor is activated/deactivated by the main electrical contact cog which in turn runs off the main (red) cog..
The second positive input is a pulse input from the wiper stalk which activates the wiper cycle, which moves the contact leaf cog, allowing the main circuit to take over the running until the main cog identifies it is at the "rest" position, closing the main circuit...
The problem occurs that the leaf connection becomes "bent" as it is against its spring 99.9% of the time......It becomes necessary to bend the leaf to ensure it remains fixed against its contact, unless it is at the rest position as dictated by the contact cog...
the picture below shows both the red (main) and electrical contact cog....
http://i35.photobucket.com/albums/d1...71pshopcog.jpg
Stage 1....Remove the 8mm nut holding the wiper arm to the stalk...
http://i35.photobucket.com/albums/d1...r/IMGP1450.jpg
Stage 2.....Remove the wiper arm, disengage the water pipe and remove the under lamp panel....Open bonnet
http://i35.photobucket.com/albums/d1...r/IMGP1454.jpg
Stage 3....Unplug the brown multiplug attached to the back of the lamp unit and unscrew the 12mm securing screws....
Stage 4.... Remove the motor, it can be seen below with the florescent green markings on it...
http://i35.photobucket.com/albums/d1...r/IMGP1462.jpg
Stage 5.... Place the unit on a bench noting the way the top is fixed to the main unit....There are four MAIN securing tabs that need to be released from there retaining clasps , it is likely that a couple of the retaining clasps may snap......Using a couple of screwdrivers, negotiate the back cover off
http://i35.photobucket.com/albums/d1...r/IMGP1466.jpg
Stage 6...Push the wiper spindle out of the back of the unit, releasing the cog actuator securing mechanism and the main cog spindle actuator...
http://i35.photobucket.com/albums/d1...r/IMGP1469.jpg
Stage 7.... Remove the metal backing plate...to reveal the guts of the unit..Note the position of the red cog with regard the black line across it....
http://i35.photobucket.com/albums/d1...71pshopcog.jpg
Stage 8...remove the main, red cog, the white motor cog and the small contact cog....the unit will look like below... http://i35.photobucket.com/albums/d1...P1472pshop.jpg
Stage 9...Note the metal leaf outlined above, this needs to be bent using long nosed pliers.., grip the metal leaf and twist the pliers clockwise, fractionally to bend the leaf tight to its contact causing an open circuit (when the small cog is replaced it will close the circuit)...
Stage 10....Replace the small/connector cog, with the flat side against the leaf connector...,replace the large white cog and the red one....Apply plenty of grease to the cogs and surrounding areas...Then refit the metal backing plate, pressing it securly into place.....
Stage 11...Replace the spindle, actuator mechanism and actuator, ensuring it fits securely in place...do not be concerned that the actuator may look different than it did when taken apart, the unit will "self adjust" when reconnected....
http://i35.photobucket.com/albums/d1...r/IMGP1478.jpg
Stage 12....Refit the motor back cover and Plug the unit back into the wiring loom and turn on ignition, this will allow the unit to carry out a full cycle and position the spindle into the "rest" position..
Stage 13....Refit the motor back to the car in the reverse of the dismantling instructions....
cheers
jod


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