| Fixing stuck down "Retract" button on Electric Mirror control
Description Explains a potential cause of the "Retract" button being stuck down and how this can be fixed.
Date Fri Oct 14, 2005 5:45 pm
Type Text How-To
Viewer Comments [0 - Post your comments]
|Fixing stuck down "Retract" button on Electric Mirror control
Explains a potential cause of the "Retract" button being stuck down and how this can be fixed.
When I bought my MR2 the "retract" button appeared to be permenantly stuck down and so I couldn't retract the mirrors.
I looked around on ebay etc for a replacepment but most seller wanted to sell the complete Door Control Unit (DCU) including the electric window controls (EWC) which I didn't need...the average price for the unit was £30 + delivery.
I decided to have a look at what the problem was...I'll now try and document the inner workings and what caused my problem and how I fixed it.
I hope this helps but as per usual with these things, I take no responsibility if you damage your components or your car!
1.Remove the DCU - mine lifted out fairly easily due to 1 of the retaining clips missing - not sure how to do this otherwise.
2. Once you have the unit turn it over and you'll see 4 tabs holding the EWC in place. Push the tabs inwards using a small flat ended screwdriver. The EWC should now lift away as a complete unit.
3. Look around the edge of the EWC...you should see 4 slots where the mainboard tabs protrude from. Again, using a flatend screwdriver ease the casing away from the tabs until you can remove the casing - WARNING: BE VERY CAREFULL AT THIS STAGE AS YOU COULD POTENTIALLY DAMAGE THE CIRCUIT BOARD OR SNAP THE CASING.
Inside the unit there are several small components and tiny springs that will become loose when you remove the casing. I will explain where these go but you need to ensure you don't loose any!
Once you've removed the casing, ensure you have all the small components:
2 x "W" shaped pieces of metal approximately 3mm in length
2 x springs approximately 3mm in length
1 x plastic "contacts" holder. This sits under the directional thumb pad
1 x metal retainer - this sits inside the casing and holds the contact holder in place.
4. Look at the circuit board. one the top right corner where the retract button would normally be you should see a small rubber dome. It's secure to the circuit board via 2 rubber prongs.
On my EWC, this dome had cracked and this was the problem...
Basically, when you press the retract button, this presses down on the rubber dome which contains a small copper contact plate. the plate is forced down onto the circuit board and the circuit is completed. The shape of the dome causes the rubber to flex which causes the retract button to be forced back up to it's starting position.
Because my dome had cracked, the rubber dome was not flexing and so the switch wasn't returning to it's starting position.
5. If your dome is also stuck down, you'll need to either repair the dome or replace it. I initially tried to melt the rubber enough to seal the break. Unfortunately I didn't have the correct tools for this and so I gave up after several attempts. If you have some small soldering irons, you may be able to repair the existing dome.
If the dome needs replacing, you'll need to find something that will force the switch upwards. Whatever you use cannot be made of metal as this will cause the circuit to remain constantly connected.
I used my TV remote! The remote had previously fallen to pieces and the buttons consisted of a moulded rubber mat. there were no springs under the buttons, instead they popped back up after being pressed due again to the moulded shape.
I cut out one of the buttons and placed it in position. I've made this sound easier than it was but if you've got some patience and small scissors (I used nail scissors) all you need to do is look at the movement of the retract button and how it makes contact with the circuit.
I eventually cut the base of the button to a shap similar to the square hole where the retract button sits. the idea being that this would hold the new "dome" in place. You could alternatively glue the new dome in place but then if it doesn't work, you've got to remove it again. Apart from making the circuit board messy, it will take a lot longer!
6.Remove the TINY contact patch from the bottom of the old dome...this really is tiny so be very careful not to loose it as I'm not sure a bit of tin foil will replace it!
Glue the contact patch onto the bottom of your new "dome" and leave to dry.
Why thats drying, let's go through the rest of the pieces and how to reassemble them.
look at the casing. You'll see the underneath of the switch that selects the right or left mirror to control. Look closely and you'll see 2 small round holes and 4 slots. The 2 tiny springs go into the 2 round holes. The "W" shaped pieces of metal go into the slots accross the springs. This will all make sense when you look at it, trust me.
7. Place the casing upsidedown on a flat survace.
8. Place the 2 springs into the Right/Left switch followed by the 2 "W" pieces.
9. Place the retract button into the casing.
10. Take the big metal retainer and place it into the casing followed by the contact holder. It's difficult to explain how these are supposed to fit in. There's a rectangle cut out of the retainer which locates around 4 lugs on the contact holder. That's honestly as good as I can explain it...have a play and see how you get on; there are only 2 ways you can do this!
11. Place the circuit board ontop of the casing. Make sure you're new dome is in the right place.
12. Click the casing down until the 4 circuit board tabs are back through the casing and holding it in place. At this stage, "feel" the retract button and make sure there's good movement - obviously you won't know if it's worked until you refit it (it took me 3 attempts) but this is a good indication.
13. Fit the EWC back into the DCU and then refit the DCU into the car.
Powered by Knowledge Base, wGEric ©2002 PHPBB.com MOD
This script (Knowledge Base - MX Addon v. 1.03e) is modified by Haplo
Powered by phpBB © 2001, 2005 phpBB Group