Sunday, January 16, 2011

Myvi Auto Wind Power Window

Failure symptom : Unable to wind down power windows at driver seat

Below is the process repairing Myvi driver seat power window for handy poor man who is not willing to spend RM85 to replace the power switch. If you do not fit into this category, don’t waste your time going through the process, the trouble really doesn’t worth your engineering time vs money, new power switch is only RM85, really.


1. Unscrew
2. Open

3. Press the latch and pull the the connector out from the socket


4. Unscrew


 5. Remove the lock button


6. Unlock plastic clips


7. Circuit board detached from plastic casing. Don’t lost those small parts and springs, you will still need them later.


8. Desolder all soldering point, use the white casing to hold the circuit board up right.


9. Remove the top layer PCB after desolder.


10. There are two relays to control direction of power window.
If one relay gone faulty, the power window can only go one direction, either up or down only.


11. Desolder relays’ soldering points.
Only desolder the faulty relay if you know how to determine which is the faulty one.
How to determine, check relay’s coils resistance, it should be around 200~300 Ohm, faulty relay will likely have open connection at its coils, thus resistance at its coils terminal is likely different as your swap the probes. There will still be some resistance values on one of the direction due to the discharge diode connected externally on the coils terminals.


12. Placed in new relay.
Original Relay part number is HG4181 
(full spec can be found here http://www.tyhhk.com/pdf/HG/HG4181.PDF)
Any other relay with similar spec should fit in just nice, this is a common part, cost around RM5.50 per relay.



13. Insert those springs back to its slot. Watch for the longest spring as it belongs to the driver seat power window (the white one). You will need something to temporary “holds” those springs and sticks in its slot, hair scream is somehow useful. Apply some at the point between the string and the sticks, as it placed in the slot, the cream will hold it in the slot when you turn it over for re-assemble process later.


14. Place in all the electrical contacts. Make sure driver seat power window contact slider is positioned at lower side for re-assemble process.


15. Carefuly overturn the case and slowly pressing in from the top of the PCB.


16. Do not flip the switch untill all the plastic clips sit in its slot. Now, you can put everything back to your car.