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Power windows, Silver Shadow 11

416 Views 21 Replies 5 Participants Last post by  shadow 11
My power windows on my UK market Silver Shadow 11 have been problematic of late, first the rear passenger window stopped working, then the front passenger window quit working and then they all gave up. I removed the door cards and cleaned all the wire and switch connections and now the driver's window and front passenger window work using the driver's door switch. The rear left passenger window works from its door switch but not from the driver's door switch and the front passenger door switch doesn't activate the window motor. On testing the front passenger switch I find that there's 12+ volts on both contacts before I flick it, once I flick the switch the voltage stays at 12+ on one side and drops to zero on the other side but the earth wire simultaniously becomes live at 12+ volts. Just wondering if any of you more accomplished electrical gurus can tell me if this is normal, electrics definitely isn't my forte but an earth wire turning live when the switch is pressed seems odd to me. I know that the window motor in the front passenger door is OK because it works from the driver's door switch, I just can't figure out why it won't work from it's own door switch. Also, I can't figure out why the rear left passenger door switch will raise and lower the window but the driver's door switch elicits no response from the same motor. I've cleaned every wire connection except the B-post earth (which is difficult to access) but the earth connection looks clean with no sign of corrosion. If I take an earth reading between the motor earth and the car body there's continuity. All the micro switches seem to click when pressed and spring back when released. I think I'm overlooking something obvious that would be easily spotted by an auto electrician. Any advice would be much appreciated.
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Have a look at this article on the RROC-Australia Post-War Technical Library: Window Lift Improvement Article by Richard Treacy (for SY chassis 13754 through SZ chassis 27998, 1972 to 1989 MYs)
Your window motors have 2 wires (yellow) and they are both positive. When pressing the window switch, one wire is lifted and the motor is grounded to go in one direction. When the switch is pushed in the opposite direction, it lifts the second motor wire to reverse it.
Thanks Brian, I can't upload Richard Treacy's article, I just get error code 404 but I've read it previously and recall that he took power from the cigar lighter feed in the rear doors and used relays. My main problem is with the front passenger door where the cigar lighter facility isn't an option.
The "slow window issue" is usually with the rear windows, especially with the right rear since it is the farthest away from the power source. Also, you will find that if you double up both wires to increase capacity it will make a difference right away. Experiment with the engine running vs off and you'll see why.
The early Shadows did use a relay arrangement which was eliminated in later production.
However you do not have a slow window issue at this point, as your focus is on getting it enabled first.
Hi Wraithman, my front passenger window switch is fed by 2 wires - purple with a red trace and purple with a green trace. Both wires have 12+ volts until I press the switch, when I press it one wire stays at 12+ volts and the other drops to zero (or becomes a ground), the switch seems to work as you describe. However, there is also a black/yellow wire that grounds the switch to the B-post earth, that ground wire becomes live 12+ volts as soon as I press the switch and I'm curious to know if it is normal for the black/yellow ground wire to become live or if that signifies a short in one of the two microswitches?
Front passenger window is now working from both driver's door and front passenger door switch. I found a detached earth connection at the passenger side A-post. All windows now work but there's still no reaction from the driver's door switch to the rear passenger side window. Cut-out switch at the fuse board is good so I'll continue tracing wires and scratching my head until I get to the cause of the problem. At least with the door cards and interior handles & switch besels removed it's a good opportunity to give them a thorough cleaning and a leather feed.
Here's a known issue: The cable loom thru the door jamb gets flexed the most and consequently will weaken and break a wire. I have had this happen on 2 cars so far. I found this out by toggling the switch for the affected window while opening and closing the door sitting in the driver's seat.
If that does not yield results, one could make up a test jumper from that particular window switch to the loom connector in the footwell.
Thanks Wraithman, I'll continue working through the loom until I find the bad connection or break in a wire. I have power to all the individual door switches including the 4 switches in the driver's door, it seems that there's a bad connection between the driver's door switch and the rear passenger door switch as that's the only non-working part of the wiring now. What's left to do is simply follow the wires from that one driver's door switch towards the rear door on the opposite side until I find where the current stops flowing. I'm nearly there. I inadvertently fixed the central locking mechanism in the front passenger door when I found the detached earth connection to the window motor, they share the same earth wire loom.
My main problem is with the front passenger door where the cigar lighter facility isn't an option.
But it is an option and is discussed explicitly in the article.

Someone's clearly accidentally edited the URL for the Window Lift Improvement article on the RROC Australia Post-War Technical Library. Here's the correct one:

I'll let "the powers that be" know that the URL has been munged on the library site.
Thanks Brian, For some reason the latest power window pdf you sent gives no response when I click on it. Perhaps the problem is with the setup of my phone.
@shadow 11

The problem is I gave an HTTP link rather than an HTTPS link, in all probability. Why it should matter for a PDF download escapes me, but try it again (I've updated it to use a secure HTTPS link and tested that here). I was even getting a warning message from MS-Edge saying it couldn't download the file securely and it just stopped there.
Thanks Brian, I can now download it. I'll give the article a good study. So far I have 3 1/2 windows working well having cleaned all contacts & connections. The only switch not getting a response is the driver's door switch for the rear passenger side window which, coincidentally is the longest wire run but there's no electrical output from the switch eventhough there's 12volts to the switch. I think one of the micro switches must be faulty even though it clicks and springs back as normal. I'm going to see if I can get a couple of new micro switches and hope that will cure the problem.
I swapped one set of micro switches in the driver's door and the window problem moved accordingly so I've confirmed that the final unresolved problem is in a faulty micro switch. I like to support the usual RR&B parts suppliers but in this instance their prices appear somewhat exorbitant for the small part concerned. Does anybody know of a cheaper source for the same part as I would like to buy a few extra to have as spares? Thanks, Larry.
Give Kelly a shout at British Tool Works. He is very reasonable and mailing to your place would not be crazy.
Good work Larry. Great example of your relentless search for the fix.
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Thanks Wraithman, there's a sense of satisfaction when a problem is solved. Next issue to tackle is the seat motors.
Those micro switches are available at any electronics supply store or online through all of the usual large retailers like Ebay or Amazon. They are very common and nothing special although you may have to carefully drill through the spade tabs on them to take a tiny bolt and nut instead of a stake on connection.
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Thanks Jim, yep, finding one with the same screw on connections is the problem. I might try your suggestion about drilling through the spade connections.
Use a drill bit modified for drilling brass. Grind the cutting edge flat so it is 90° to the work surface and it won't dig in and grab.
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Many enthusiasts are not aware that both switches in a circuit must work or the window won't go up and down. Fixing a single switch will not fix the window in most cases. Replace both switches anytime you seek to fix an up and down operating issue.
Also there are fuse limiters inside the motor housing. These prevent nonstop situations if you leave your finger on the switch too long. Check these for operation. Good luck. Rollsroycerescue.
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