Bodywork, Paint, Interior, Trim, & Wiring

Thanks Bill

Looks exactly what I should have .

I have send a letter off to Painless with regards to the contact dimensions in hope it will cover the hole I have already drilled.

Bruce

My last trip to the pick-n-pull I grabbed a pair of electric window mechanisms out of a Mazxa RX8 and have been adapting one of them to my passenger's side door. Been a bit of a struggle but I finally got it to work and I have a bunch of photos I can share with y'all, though there were so many revisions along the way that some details will have to wail until I get the driver's side done. No photos in this post but I'll get them added soon.

Now the Mazda unit is not the ideal, but it is usable. It is cable operated with a fairly typical motor/gearbox reducer unit and the linear motion device is a metal track with a plastic slide that attaches to the window glass with two 6mm screws. This can be fastened to a modified piece of the old mechanism. There are two flex cables joining the track to the gearbox.

The RX7 track is 3" too long The Mazda3 track is an inch or two longer than that and has longer flex cables. A Mazda6 track would be similar, perhaps a bit larger. Any of these could be used, in retrospect the others would allow positioning the motor forward of the window track in the area where the original crank was located. But the track and one cable have to be shortened to 11-3/4" of travel.

The RX7 track has 14-3/4" of travel. To shorten it, the lower clip must be removed from the "T" shaped cutout, 3" cut off of the length of the slide, and a new cutout made in the track. I used the old end and scribed the shape, drilled around it with a 1/8" bit, used a chisel to cut between them and filed off the nubs. Crude but effective. Shorten the opposite cable.

To do that I made a new cable end out of brass. You can use 1/4" brass rod, drill a 1/16" hole in it and then cut it to length. I marked the cable, taped it with masking tape, cut the end off with a zip wheel, slid off the tape, threaded it into the hole and slid it up to the mark. Then silver soldered it, trimmed off the excess and reassembled. Perfect.

Positioning of the track can be tricky. It has two mounting studs, one of which is removed when you shorten it. I made a metal bracket to attach the remaining stud to two of the original mounting slots in the door, allowing the track to pivot. To attach the slide I cut the MG window attachment off the stock mechanism. This has two spring loaded pins on a sliding bar. I welded a reinforcing strip to the center of the bar and then drilled and tapped that to bolt on the slide.

Now, the angle of the slide needs to be pretty close to the angle of the window tracks. It is possible to cock the window and this was where the trouble occurred. I ended up with the new track very slightly angled forward at the top and it has worked for me. If your reinforcing strip is long enough you can have several sets of mounting holes at different angles. Each may require slight variations in your pivot bracket but the sliding bar will allow some movement. Any angle other than the one that matches the window tracks will cause the cables to flex or the motor to move, another instance where the Mazda3 unit may be better suited. I originally came home with Mazda3 tracks but returned them to get the RX7 ones. In retrospect I think that was a mistake as the motor sat right on top of the front window track and there isn't much sheet metal there to bolt it to.

Now the switches are another item entirely. I came home with two passenger side door switches. The motors have 2 leads, you switch them to reverse. Simple enough. Any double pole double throw switch will do that. However, that's not how they wired them. They had a driver's side master. So these switches are more specialized and so far I have not been able to sort out how to make them work with only one switch. It must be possible, I just can't see how.

One side of the switch has 3 contacts. Spring loaded to center of course. The center contact makes with one pole in standard NO fashion. The other contact is the same but also closed when the switch is centered. So one contact is ON-OFF-OFF and the other is OFF-ON-ON.
The other set of contacts is reversed but shares a connection with an adjacent pole, in other words the switch sections have one pole bridged. Between that and the center-ON bit I haven't been able to come up with a circuit that works without shorting out. But it has to be possible right? I mean, you can raise and lower the passenger's side door without touching the other switch so there has to be a way. I just don't know what it is.

Anyway, photos later.

Jim



Edited 1 time(s). Last edit at 12/17/2017 12:05PM by BlownMGB-V8.

You guys have probably seen these folks advertising in street rod mags [www.specialtypowerwindows.com] but they have them that fit in the early cars and are not terribly expensive.
Dave

Dave, the ones I was able to find said they needed 8" below the window. Clearly you had a different one in mind. Looks like price is around $400?

Here's the RX8 window mechanism, laying on the MGB door, approximately in the location where it will be mounted, though the track is 3" too long.



Here you can see the difference in original curvature, and reduced to match the MGB window.



Here the end is cut off and the new T shaped cutout drilled. Some chisel and file work and it is ready.



This is my pivot bracket. Eventually I welded studs to it once I knew where I wanted them.



My outlay so far is $80. I found a diagram that I think explains the switches, both set of contacts are grounded in the center position and power is applied to the unbridged contacts. I should be able to work with that.

Jim

Real sports cars don't even have side windows, much less electric windows. Just when I thought you ditched the sissy shifter, now this....

It's lighter than the mechanical window mechanism. Works better too.

Jim

I like the lighter part. Maybe even swap the glass for Lexan.

If you did that you could dispense with shortening the track if you wanted. Just provide a stop. Save several lbs that way.

Jim

I got the Mazda window switch to work so that's a thing. The red and the green wires to the motor, Green and yellow to + and the other two to - and it works just fine. Minor adjustments to the track for better speed. Need to make a bezel to mount the switch in the door panel and hook up power. On to the other side.

Jim

Finished the job today and here are a few cues:
The track gets shortened 3" to 11-3/4" of travel and then you have to use every bit of it and it has to be trimmed at the bottom to match the bottom of the door and positioned right against it. No extra space. At the top it interferes just a bit with the lock rod but it works. The track has to be accurately parallel with the front window track and fixed at that angle so it doesn't move. This positions it near the rear of the door latch cutout. I cut out the section of the original regulator that engages the slide across the bottom of the glass, trimming the pieces it pivots on to make a pair of round buttons that help when installing it in the slide. A piece of 1/8 x 1/2" flat steel about 8" long tackwelded into the channel between the buttons gives enough thickness to drill and tap to attach the track slide to the window. Position of the first hole is roughly an inch from the end which in combination with the track location sets the raise limit. I mounted the track first then marked the flat, then drilled and tapped for two 6mm screws. This attachment also has to match the track to the angle of the front window channel. I trimmed the door to mount the motor. Used new rocker switches which fit in the original crank handle cutouts with trim pieces and wooden stops glued to the back to prevent rotation.

Mounting the track in a fixed position helps to prevent cocking of the glass when the window raises or lowers Any lack of precision in matching the front angle will cause the track to fight the channels but the bottom slide can compensate by moving.

The end result is quite good. Just like the windows in a brand new Mazda 3. Quick up and even quicker down. Total cost was $100. The weight of each unit is 1 pound less than stock, however the switch, wiring, and slider from the original regulator eats into that by a few ounces. Still, noticeably lighter than stock.

I think there are probably better choices available. I used the RX8 units. The Mazda 3 ones have longer cables and will allow positioning of the motors farther forwards in a dead space and this can be done without cutting the door for motor clearance so those should be better. More has to be trimmed from the track but that does not change the work required to do it. I thought the RX8 ones would work better but they did not. There may be something else that is a better fit, there might not be. Overall, definitely worth doing and the second door was much easier than the first one.

Jim

I don't read instructions.....I just look at the pictures. What? No pics? :)

Nah. I didn't have time to take them on this one. But the good news? I'm to the point where I can drive my car again. That's worth every picture I didn't take.

Jim

A body shop/hot rod shop guy here was going to experiment with some Cobalt rear window motors/cables. It looked like they could work using the existing window tracks. I haven't talked to him lately though.

Will there be a problem with the later MGB doors that have the internal crash beam?

I can reach the passenger window crank while driving so I see no need for electric door windows, but the rear windows in the GT can only be reached by getting out of the car since the set head rests interfere with reaching back while seated. Making these electric is worthwhile to me. I have heard of attempts to use minivan motors for swing out side windows but never a completed installation.

I used to feel the same way about it. But, for a number of years I had trouble with the windows being stiff. Which was also leading to circles in the door cards where the knob dug in. And leaning over and pushing a button is a good bit easier and less distracting. The weight loss is just an excuse. Am I getting lazy? Nah, just getting older. I want to keep driving it after I can't work on it any more. Selfish that way.

Should be no problem with the door beams since it's all on the inside of the window.

Jim