Rear wiper not working
- Thread starter micrapaul
- Start date
I've locate the relay now. Can this be tested or is it a case of replacing with another. There is no click when the switch is turned on. Also do I need to get exactly 12v at the motor because today my multi meter showed 11.97v!!
pollyp
Club Member
long as it's near enough 12v. does the voltage to the motor change as the stork is turned on/off? if it's constantly 12v, either the relay or the stork switch is stuck/fused on.
the relays have a diagram of their pin-outs. u could check if the electromag coils Ohm is intact or burned out.
could prob swap over the rear demister relay next to it to check if it's a relay or circuit problem.
but you say the motors connector is showing 12v, a normal working motor should move but urs don't so the fault is the motor failing to convert voltage into movement. sometimes the sliding contacts inside the motor assembly can wear out.
There's always 12v at the motor to reset it back to park. The other 12v from the relay( which you're not getting) is for normal operation. Its unusual for relays to fail. Check for ground and 12v at the relay coil.
The switch works for the front wipers and and front and rear washers, its only the rear wiper that doesn't respond. I will try swapping the deminster relay but it doesn't appear to be along side the rear wiper one.
Attachments
Thanks for that.
pollyp
Club Member
according to the wiring circuit, the motor receives constant 12v feed via blue wire (to keep gear spinning during wipe till its returned to "park" position), ground via black, and a switched 12v via light green wire (to trigger movement when gear in "park" position).
I would measure light green & black wire whilst switching wiper on off to check all the circuit & relay is actually working, sending a trigger voltage to the motor.
if the circuit is working ok, next is check the motors circuit is intact.
motor is usually still in Park position awaiting a trigger voltage from lt green to set it off. so measure the ohms between where the lt green & black wires would go on the motors connector and it should be intact.
if there's no reading then either the sliding contact on the spinning gear for the 12v trigger circuit is worn out (common) and/or the motor is worn/damaged.
the rivets holding the cover plate over the spindle gear can be grinded off to expose the sliding contacts and inspect their condition. you'll need to carefully drill & tap new holes to screw the cover back on.
here's when I disassembled the front wiper motor, rear motors the same procedure
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-116#post-701391
I would measure light green & black wire whilst switching wiper on off to check all the circuit & relay is actually working, sending a trigger voltage to the motor.
if the circuit is working ok, next is check the motors circuit is intact.
motor is usually still in Park position awaiting a trigger voltage from lt green to set it off. so measure the ohms between where the lt green & black wires would go on the motors connector and it should be intact.
if there's no reading then either the sliding contact on the spinning gear for the 12v trigger circuit is worn out (common) and/or the motor is worn/damaged.
the rivets holding the cover plate over the spindle gear can be grinded off to expose the sliding contacts and inspect their condition. you'll need to carefully drill & tap new holes to screw the cover back on.
here's when I disassembled the front wiper motor, rear motors the same procedure
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-116#post-701391
I can confirm that the wiper is working when connected direct to the battery and as the relay is also ok I can only presume the fault lies with the switch on the column stalk? The operation for the front wipers and both front and rear washers is fine. How easy is the stalk to replace?
