Right, they are all in now and working, so I’d thought I’d write a short
post just in case anyone thinks of doing this in the future. For reference, my
5 is a mk one 1997 1.8i with manual windows factory fitted.
The wiring is very nearly all there. If you remove then centre arm rest bit
(5 screws I think, requires gearstick removal) your find a 6-pin plug - this is
the plug for the switch. The blank panel easily comes out with 2 screws. Put
the switch in, screw in (3 screws, so I sourced one lying around the garage),
connect to plug, then replace the entire console.
The door part is slightly more tricky, but not much. First thing is to
remove the door card. This involves taking off the door handle etc (to get the
winder off put some string around the handle and pull in different directions
until you catch the clip (you don’t need much force if you get the angle
right). For ease, I then removed the plastic sheeting, sliding it off in one
piece for replacement later. Next is removal of the window, again simple, put
the window about half way down and (whilst person #2 holds the glass) unscrew
the bolts holding it in, as well as the white stops. It should easily slide
out.
Then take out the manual window regulator (after undoing the three bolts).
Getting it out of the door is tricky (you have to find the correct angle), but
can be done with some patience. Next remove the small grommet in the door, not
more than 30cm from the original bolt holes (the new bolts go in slightly
different places).
The wiring is best reached (I found) by unclipping the black tubing that
protects the door speaker wire as it goes into the door. Pull the speaker wire slightly
out of the car (towards the door) and your find the electric window wires attached,
nice and easy.
In true Haynes style, installation of the electric motors is just the
reversal. Just a couple of things to point out regarding the wire. I found out
which way round the cables go by seeing if the window went down when I pushed
down, if not, then it’s the other way! You do have to add about 30cm of cable
each way, on both sides of the car, so make sure you use cable with a higher
rating than the electric window fuse. Its up to you how you connect the cables,
I soldered mine personally, then covered them with a bit of insulation tape.
Put the lot back together ad you should be away. Please note that I relied
heavily on the enthusiasts guide to do this, and it is recommend you at least
read the relevant sections in case I forgot something.
On a side note, whilst the window is apart it’s the perfect time to re-grease
your window runners.
Please also note that not I, MX5 OC, nor anyone else can/will/want to take responsibility
for what you do to any car. I hope the above information will help, but follow it
AT YOUR OWN RISK. (And all the other normal legal stuff…).
So, as a result of this, I now have a mark 1 manual window regulator to sell
(only one - a friend broke one 
). Please see in sale section if interested (will put up within a couple of days)