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Discussion Starter #1
I've been looking at adding/converting my GT to power windows. And, I thought I'd try to collimate all the advice and experiments done over the years into one place, and maybe update that. Hopefully everyone can use this thread as a resource/reference rather than thread-hunting like I did (at least until this thread is also obsolete). Feel free to share what worked and didn't work with your setup.

First, a list of relevant threads. If anyone remembers some particularly good ones, post and I'll update this.
Gordo's Electric Window Adventure! - Part Zwei
Long Awaited - Opel GT Power Window retrofit

From what I can tell, consensus seems to be to use late 90's Honda Civic power regulators. The reasoning for this is that they are about the same length as is needed for the GTs. Some people use Accords, some people use front vs. rears, there's several slightly different styles. Most people think that all window motors are the same size.

Some people replace the whole Opel mechanism. Some people keep the sliding mechanism but replace the cabling and the motor.

Reasons for replacing the whole mechanism:
  • The Honda Civic ones are a very close fit.
  • The "slider" is what causes so much resistance, so it's best to get rid of it.
  • No issues with dealing with cabling or cutting or fabricating.
Reasons for keeping the sliding mechanism and only replacing cable and motor.
  • Opel windows have holes and bolts in them to mount to the mechanism and the bottom grabbing method of modern windows is difficult to adapt.
  • The Honda Civic ones aren't actually that close of a fit.
  • The slider rail that the rising/lowering shuttle rides on is curved and it is difficult to make the Civic one match.
  • No issues dealing with slider alignment or adjustment.
Less Population Options:
  • Gordo tried to use a scissor mechanism, usually used on heavier windows. He got it to work but this required skinning a scrap door and he doesn't think it's worth it and opted to use Civic ones.
  • Some people have used "SPAL" kits, which seem to be not viewed very positively.
Other notes:
  • The alignment of the GT doors is often off, without being visibly so. Just from throwing the door closed by the upper corner. This makes window closing difficult.
  • The interior alignment of the Opel sliding mechanism has several unintuitive adjustments, but do look for them. There's a procedure to adjust them out there...
... This top post will be edited (and is welcome for moderators or whoever to edit in the future if I'm not active).
 

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Discussion Starter #2
And for some discussion...

If you're not going to keep the rails from the Civic regulators, and you're going to be cutting the cables anyway... then I can think of no particular reason to use the Civic regulators other than they're considered rather durable compare to other brands.

While I was taking window switches from a Dodge Caravan, I noticed that the use a double-slider instead of a single, but with a single motor and cable in a figure-8.

Since it doesn't matter what size the sliders are if you're re-using GT ones, I did notice that the Caravan motor is significantly larger (and therefore more powerful) than the Civic ones. It's possible it's just geared faster and ends up no more torquey, though I suspect there's a regulation about how fast windows can close and in general it just means a beefier motor.

Civic on the left, Caravan on the right:



Measurements are just pixel counts. What matters is that the relevant guts of the Caravan motor are 150% the size of the Civic one.

...

My plans tomorrow are to return the Civic ones and pull two Caravan motors unless someone talks me out of it.
 

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Just Some Dude in Jersey
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Good observations and condensation of the points in my threads. Here's a couple more to add:

The GT slider rail acts as accident protection in the otherwise hollow, thin-skinned, door.

Honda ones are cheap and easy to find.

:)
 

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Opeler
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Agree, and good summary above. When I did my conversion it was surprisingly super easy. Made my own cable guide blocks to fit the Opel slider at the top and bottom and really that was the only custom fabrication required. I plan to do this conversion on my wife's future GT.
 

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Just Some Dude in Jersey
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Here's some thoughts to ponder from the Modification Commander-in-Chief:

Opel GT windows have always been the worst POS windows I have ever encountered in the 40+ years of my adult life.

The nylon slider guides and the pulley quality and position are what I think are their biggest problem.

Replace the nylon sliders with rollers would be one way to replace them with something less prone to binding.

Mount the cable pulleys as high as possible and replace them with better ones.

Mount the cable anchoring point on the window lifter as low as possible.

The above 2 are to stop the cable from being pulled sideways as the window nears the top thereby causing an exponentially increasing amount of force to be used to get the window to close that last inch or two.

One reason that scissor lift windows work so well is that they push up from the bottom, instead of lifting from the top, plus leverage and other reasons.
 

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Discussion Starter #6
Honda ones are cheap and easy to find.
As are Late 90s Dodge Caravans. My local Pick N Pull has minimim a half-dozen year-round. Probably a dozen of the early 2000s which are probably equivalent.

Replace the nylon sliders with rollers would be one way to replace them with something less prone to binding.
Speaking of which, Caravan sliders, being dual-rail, each have 2 pulleys. Versus the Honda ones that have 0 pulleys.

... I'm thinking Caravans are thoroughly the better choice. Only downside is they're a lot harder to remove at the junkyard if you're buying used. Like, 4x the work compared to the Honda ones.
 

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Just Some Dude in Jersey
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Certainly as the years go buy, better or simply cheaper or easier to get alternatives come to the forefront. Generally, the scissor lift type is used on high use windows, like driver and passenger doors, and or larger SUV or truck windows. Often you'll find the driver/passenger doors on bigger vehicles will have the scissors and the generally smaller and less used rear seat windows will have cables.

When I was looking at various types of window lifters, I considered the dual cable type. They are definitely an option to consider, especially since skewing of the window in the track is a primary cause of binding on our cars. I'm sure a dual cable type could be found that would work. Size and available space is definitely an issue in our cars. Many modern cars have pretty flat window glass compared to our curved windows. Be VERY aware of that before you blow your scarce cash. Generally, you should choose a type with a lifter rail that matches the arc of the GT window tracts. A too straight rail may cause a binding issue as the bottom of the glass where the lifter attaches tries to follow the arc of the GT window tracks. A floating rail may be able to flex or pivot outwards to follow those arcs, but that might cause the motor to also swing outwards and hit something.

I found the install of the electric windows to be quite a fun project because of all of the factors you have to take into account. There's all sorts of stuff to consider, like what I mentioned above, that make it challenging and fun. I like a challenge and I don't care if I fail and have to start all over again with an entirely new concept, like the scissor lifters. The big revelation of the scissor lifters is realizing that you have to take into account the ratio of the height of the window opening compared to the height of the body of the door. Generally you want the body of the door to be several inches or more bigger in height than the height of the window opening. The bigger the better, in order to provide enough room for the window to go all the way up and all the way down below the window sill, plus provide enough room for the mechanism. You will have noticed in the scissor lift window videos that the space runs out and there was maybe 1/4" to spare at the bottom of the door in order for the window glass to recess below the window sill. This is why I gave up on the scissors, I couldn't guarantee that the window would retract all the way down below the window sill before the mechanism crashed into the bottom of the door. It probably would have worked, but I didn't want to go to all the trouble if installing them, only to discover that they wouldn't work. Consider that modern vehicles have much higher window sills than older cars. the body of the door has a much greater height than the height of the window opening. This is probably a good thing. Or maybe not.

Just some thoughts for you to consider as you make your choice.
 

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Discussion Starter #8
They are definitely an option to consider, especially since skewing of the window in the track is a primary cause of binding on our cars. I'm sure a dual cable type could be found that would work. Size and available space is definitely an issue in our cars. Many modern cars have pretty flat window glass compared to our curved windows. [...] Generally, you should choose a type with a lifter rail that matches the arc of the GT window tracts. A too straight rail may cause a binding issue as the bottom of the glass where the lifter attaches tries to follow the arc of the GT window tracks.
Oh, if you plan on swapping out the slider and rails, then the Honda ones are still your best bet.

However, if you're keeping the original Opel ones and just replacing the motor and cables and rigging those to Opel hardware... I think Caravan (or honestly, probably a million others) is the way to go.

Another thing I should add to my notes, there is both wet and dry lube sprays available at Walmart in the automotive section (by the hitches) for the tops of RV slide-outs. I was going to ask whether the wet or dry versions would be best for lubing the Opel window tracks (or neither).

I found the install of the electric windows to be quite a fun project because of all of the factors you have to take into account.
Your type of fun is my type of frustration. It's not fun for me to solve problems that can fail for 20 different hidden reasons on a task that only matters to me that it works vs. doesn't work. To me that's like reassembling a 2x4 that went into a wood chipper, so that you can use it as a 2x4, inside a wall. I'd rather use my problem solving on something that has noticeable impact. Like, how your favorite thing is building dashes. That I understand, because every decision is noticeable and unique. Different strokes and all though.

Consider that modern vehicles have much higher window sills than older cars. the body of the door has a much greater height than the height of the window opening.
Indeed, my biggest pet peeve about modern cars. Feels like you're driving inside a knight's helmet. Stupid windows taper to little eye slits at the back. No visibility, whole vehicles disappear behind the obese pillars. I think the goal previously was "How big can we make the windows? I guess only 50% the height of the door because otherwise they can't go down all the way".
 

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Detritus Maximus
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Indeed, my biggest pet peeve about modern cars. Feels like you're driving inside a knight's helmet. Stupid windows taper to little eye slits at the back. No visibility, whole vehicles disappear behind the obese pillars. I think the goal previously was "How big can we make the windows? I guess only 50% the height of the door because otherwise they can't go down all the way".
It's not just modern cars...try parallel parking a 73 Mustang fastback with bigger wheels and tires on the back plus an 1 1/2" lift...kind of like this. Not much fun.
CC-52-015-800.jpg
 

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Just Some Dude in Jersey
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It is for crash protection when a normal sized car gets hit by and SUV. My Pontiac Solstice has window openings only about 10" high. I can barely or not at all stick my head out the window when backing up in a difficult situation. Pic of both my cars, compare......
428064


Same height, same length, Solstice is about 4" wider. Look how ridiculously small my wheels look next to the Solstice.
 

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Opel Key Master
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The problem isn’t the motors power, it’s when you replace h GT window surround rubber with the new stuff, there is just too much drag. They work great with old dry tracks, but new stuff not so much. Jennifer Betz Windows seem to work really good, but I wonder still about the track rubber
 

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Just Some Dude in Jersey
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I heavily trimmed away the window track rubber at the zig zag area at the front of the door below the window sill. Huge bind point there.

It also appears that the new window rubber does not like the metal clips in the metal tract that holds the window rubber in place. I presume that there is a thickness or size disparity between the oem and the new type.

Also, the window channel rubber we are presently getting is made from a "grippy", high traction, squishy rubber-like material. I'll betcha it's not even rubber and that it's actually urethane. Urethane = bad, Rubber = good. But rubber stuff is VERY expensive to have made these days, so everyone is making stuff out of black-colored urethane. Urethane is not stable and it doesn't bond with anything and is always in a pseudo-liquid state. It eventutally migrates out of whatever you mix it with. The oem "rubber" was not grippy. It may have originally been a plastic-like material. Yes, all the examples I've seen of oem rubber have been aged dried window rubber, but I'll bet it was still a lot harder and stiffer that the new kind. The new kind is so flimsy that you can have fun flicking and playing with it while your arm rests on the window sill. No modern car I've had has window rubber that is that grippy and flimsy.
 

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Discussion Starter #14
I've learned way more about window switches than I ever wanted to.

Since the Caravan switches have a nice feel to them, and a compatible wiring harness, I'd also taken the switches to repurpose in my GT.



I made some presumptions about how easy this would be and... boy was I wrong.

First things first, let's just take a poke at the switches. Simple enough, right? Hrm. There's a 14-pin connector (12 in use) just for 2 front and 2 rear windows.

In my head I'm thinking 2 power inputs, 2 outputs for each windows motor (8), shouldn't need more than 10 wires but okay, 12 is fine.

Let's just crack the case open. I'm expecting to find 4 double-pole-double-throw polarity-reversing switches. Maybe they'll be mounted on a circutiboard together to save on connector costs. Instead I found this:



It's at least a 2 layer board (with risers instead of vias) and a hundred 90s electronics components. It has a chip, and a transformer... why?

And how do these switches even work?



Each switch direction (i.e. window up or down) has a single metal push pin that plunges through holes in the first layer of the circuitboard, and depresses the switch metal inside circuit board housing. (Except for a light-press on the driver's window which depresses a switch on the top layer, a harder push which pushes this metal into another pin below it on the next layer).

Why?

And further, these aren't DPDT polarity-reversing switches. They're single pole double throw switches. How are they reversing polarity (of 2 wires) with only a SPDT?

I get out a pen and make a matrix of the connectivity of every terminal pin to every other terminal pin, and depressing every switch in every direction to record what changes. It gives me no hints.

Let's just look up the wiring diagram. Which isn't published. I get a hold of a Japanese one which has all the wrong wiring colors but does at least list left-hand drive variants.



Hmm, okay, that's clever. Both motor leads are tied to ground. But when you switch only one switch, (single pole), it disconnects that side and connects it to the positive rail, spinning the motor one direction. You can't push both at the same time, so if you switch the other one, it connects the opposite motor lead to the positive rail and turns the motor the other direction.

Okay great, that works. But whyyyyy? Why not a DPDT? Why use two independent SPDT?

Why this whole complicated circuitboard? What else is it doing? Why not just 4 DPDT switches instead of this thing has has to be delicately hand-assembled with all the snap-action leaf springs?

Maybe it's all there as part of the "auto-down" feature, and was the best they had for the mid-90s (which, considering they were still installing tape decks in 2005, is probably 1980s tech since the auto industry is like, 15 years behind common electronics).

...

I map the circuitboard manually because I don't trust the wonky diagrams. Got a pinout with the wrong colors but at least functions described and matches my observations:


(just in case anyone ever wants to do this exact thing themselves)

And the wires that match every North American caravan I've looked at (a dozen by now):


...

Now, these are all supposed to go through a "Fused Window Circuit Breaker", which is maybe just a PTC poly-fuse (autoresetting). It's supposedly in the car somewhere, I don't think it's in the fusebox, haven't been able to find it. This makes sense, if a window jams (like on a child's neck) you want the power to cut. Ditto if you hit up and down at the same time and cause it to short.

...

I've been considering whether I want to install them in the door itself, or just integrate it into the center console somewhere and have a lot fewer wires to have to run to the doors.

...

I should probably make another thread about power locks, but, after I got power windows figured, I thought "Locks will be easy, that's a separate switch, it'll just be a 4-wire DPDT!" ... wrong again!



The door lock switch also has a circuitboard with components on it. Whyy? Also, they're single-pole-single-throw switches, not even double-throw switches. Also there's only 3 wires on the output. How do you get reversing polarity with only 3 total wires?

Well, that's because they don't actually control the locks. The switches switch various resistors into and out of the circuit. These then go back to a small analog computer-like box called a "MUX" or Multiplexer. Whyyyyyyyyy? Why is there a logic circuit involved? I just want to lock or unlock the doors! They can only do 2 things: lock, and unlock! ("Why" is because the locks do things like automatically lock when you drive faster than 30km/h, and wait before closing to lock, maybe).

I decide to rip apart the circuit and repurpose them, just re-wire them as SPDT power switches... but I can't. Because the switches themselves are only single-throw. They don't have to two positions. They just have off and on.

However the passenger window switch is, while not a DPDT switch, it's the same as on the driver's door, it's a pair of SPDT's with both sides of the motor tied to ground initially.

Even though they look similar (identical on the outside), the brass part is common to the copper part on Lock switch, but independent on the Window switch.

I check the wiring diagram...



... it shows the lock switches only have 2 wires (not 3 like mine) but using double-throw switches. Still uses resistors and a MUX, but, different than the hardware I found.

...

Before I found the Japanese wiring diagram I've spent the last couple weeks taking measurements of the doors and switches trying to divine what they're supposed to do.

I still can't figure out if the redundant circuit board wires are supposed to be in common (just for extra current handling) or whether they do something independent of each other.

Are everyone else's kits this complicated or do yours all just use DPDT switches for all this?
 

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Just Some Dude in Jersey
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My scissor lift windows had overloads and memory built into the motors, use any ole simple switches you want. Your selection appears to have it all built into the switch circuit board. Meh. Maybe that's the wave of the future, cheaper motors with no logic. I have a flat screen TV that has all the logic, connections, and web capability in a box connected remotely to the screen unit. The idea apparently didn't catch on and they went back to building all that stuff into the screen.
 

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Discussion Starter #16
Well I've successfully wired it all up into a vehicle.

Some notes:

- A reminder, when you can't figure out why someone did something one way, presume you're wrong and they had a good reason. I suspect the reason that the window switches don't just use simple DPDT switches is because if the driver tells the passenger window to go up, and the passenger tells their own window to go down, this will create a short circuit. With the design used here, if you put switches in opposing directions, you end up disconnecting the doors from power (both side of motor go to the same wire). Otherwise you'd blow a fuse.

- Even this generation of Caravan window regulators have a built in PTC overtemperature components on the motors themselves. I forced the motor up when it was up, and after a second or two it shut itself off and would only buck a 1/4" at a time until I let it cool off. That's great to know the protection is built in. I don't know if that was true on the Civic motors.

- My plan of using 2 extra passenger window switches instead of the MUX'd lock switches worked perfectly. I wired them up as lock switches the same way the window switches were wired. Used the same amount of wires. You use the output of one switch as the input to the other, and the output of the second to control all the locks at the same time from the passenger door. (Meaning 4 control wires get uses between the driver and passenger door, plus power for the LED switch lights and locks themselves). The housings were compatible so I dug the guts out of one and swapped it into the other. It meant I gutted 3 different caravans to get all the switches I needed, but, there's lots to choose from.

I'll take pictures of the circuit diagram some other time, just wanted to share that yes, it all worked. 2 front windows, 2 motorized pop out windows, and the locks.

Now to try it inside the GT.
 

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Just Some Dude in Jersey
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FYI: When you are routing your wires through the door hinge area you'll quickly discover that there's no room and no holes. Remember that it's better to bend a wire over a long span than a short span. I found that it was best to pry up the metal at the top of the top hinge, feed the wire along the top of the hinge and then into the small cavity that the hinge recesses into, then...IMPORTANT.....feed the wire down to near the lower hinge and either find a hole there or drill one to feed the wire to the under the dash area. If you try to exit that cavity up near the top hinge, the wires will either bend excessively or move back and forth in the hole, as you open and close the door. If you route the wire down to the lower hinge, then it only bends slightly with door movement.
 

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Discussion Starter #18
you'll quickly discover that there's no room and no holes
I can make holes.

Remember that it's better to bend a wire over a long span than a short span.
I don't plan to bend it at all.

Wires handle being twisted far better, and, twisted over a longer distance. For example, if you twist 6" of wire 90 degrees, it's easy on the wire. If you twist 1/4" of wire 90 degrees, you'll soon rip the insulation and brake the strands.

So ideally what you want is to have the wire exit the door, then make a 90 degree bend and rise up or drop down in a column that is in line with the pivot hinge of the door, the point the door rotates around, then bend 90 degrees and enter the body. The 90 degree bends are fixed, and the whole wiring harness twists during the column that follows the hinge line. That appears to be how every OEM power door handles this.

How closely you can imitate that on a GT that wasn't designed for it, is the challenge.

I found that it was best to pry up the metal at the top of the top hinge, feed the wire along the top of the hinge and then into the small cavity that the hinge recesses into, then...IMPORTANT.....feed the wire down to near the lower hinge and either find a hole there or drill one to feed the wire to the under the dash area.
Yep, some variation of that seems to follow the OEM design of most cars. I think your experimental results line up with what's engineered.

It's not a priority for me, other than making sure I don't paint myself into a corner. But when I do get around to it I'll try to show it off with pictures.
 
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