If you become a supporting member you can download the CMC assembly manual. It has a wiring diagram that may or may not have been followed in building the car.

I am pretty sure the Sierra-Madres convertible top won't fit. You may want to consider getting a top from Vintage Motorcars.

A Siera-Madres convertible top will be difficult to fit if, it fits at all!  Plus you'll need a original carriage frame that is ridiculously expensive.  I strongly suggest you buy a top assembly with new steel bows and new header bow with latches applied from Greg at Vintage Motocars Hawaiian Gardens CA. this will fit a CMC and you'll be much happier in the long run.

Electrical butt connectors are a shade tree nightmare, for reliability I will also suggest a Speedster specific wiring harness and schematic from Vintage Motorcars.

Alan is saying that because he once renovated an older CMC build where the original builder had used red wire exclusively everywhere in the car.  Same size wire everywhere, too.  🤦‍♂️

I installed a Vintage convertible top in a CMC and it fit pretty well. It would have been an easier install if I had used Vintage top bows rather than CMC but then I’m a stickler for punishment.

On wiring, I would endorse leaving it alone, but if you really want a weekend project, pull it all out and install a tried and proven Vintage wiring harness.  I recently tried to make heads N tails of the CMC wiring diagrams circa 1984 or so and there are enough discrepancies and outright errors in them to avoid them in favor of the Vintage version.

My JPS has a few white wires thrown in, for appearances, I'd guess.  If it works, best leave it alone. At least that's how I look at it.  I once mistakenly swapped the alternator idiot light wire with the one that lights up the instruments (while swapping out my tach) .  That proved to provide a few interesting miles where my battery went dead a few times, except when I was driving at night.  See if you can figure that one out.  Eventually, I did.

So, now you understand,  "Welcome to the madness", Jack !  Best of luck.

@Alan Merklin posted:

A Siera-Madres convertible top will be difficult to fit if, it fits at all!  Plus you'll need a original carriage frame that is ridiculously expensive.  I strongly suggest you buy a top assembly with new steel bows and new header bow with latches applied from Greg at Vintage Motocars Hawaiian Gardens CA. this will fit a CMC and you'll be much happier in the long run.

Electrical butt connectors are a shade tree nightmare, for reliability I will also suggest a Speedster specific wiring harness and schematic from Vintage Motorcars.

Thanks for everyones replys, I have unfortunately already bought the sierra-madres top before the car was shipped to me.. I spent good money to ship it here, It seems the steel bows are long enough and would work, I also have the fiberglass bow with latches. What problems have speedster owners ran into using Sierra-madres with CMC? And can you please clarify the "original carriage frame" I tried doing research on this but did not find what I was looking for.

I will look into Vintage motorcars top and see if I can get a refund/ship back my Sierra madres top.

@Alan Merklin posted:

A Siera-Madres convertible top will be difficult to fit if, it fits at all!  Plus you'll need a original carriage frame that is ridiculously expensive.  I strongly suggest you buy a top assembly with new steel bows and new header bow with latches applied from Greg at Vintage Motocars Hawaiian Gardens CA. this will fit a CMC and you'll be much happier in the long run.

Electrical butt connectors are a shade tree nightmare, for reliability I will also suggest a Speedster specific wiring harness and schematic from Vintage Motorcars.

The butt connectors also change the color and thickness of the wire, It really is a mess.

@Jack Bolton Perhaps it would be easiest if you provided us the information of what exactly you purchased from SMC.  SMC offers a few top options: just the canvas top for original speedsters, canvas tops for replicas, frame kits for both, or a combination for both.

@Kevin - Bay Area posted:

@Jack Bolton Perhaps it would be easiest if you provided us the information of what exactly you purchased from SMC.  SMC offers a few top options: just the canvas top for original speedsters, canvas tops for replicas, frame kits for both, or a combination for both.

Of course! I purchased the High Bow Frame and the Canvas for replicas. the Front fiberglass bow
Canvas top/Frame
https://sierramadrecollection....laZBl3xoCA_sQAvD_BwE

Top bow
https://sierramadrecollection....4&pr_seq=uniform

Window Curtain Set
https://sierramadrecollection....w-curtain-set-p18205


The window curtain set does not align with the holes in the bolster at the doors edge.. This makes me feel like Sierra Madres not built to fit a CMC as stated.

Sierra Madre sells Porsche parts. AFAIK, when they say “Speedster replica” they mean remanufactured NLA Porsche parts, unless specified for Beck/VS speedsters and Spyders.

OK, so the good news is that I looked at your Sierra Madre links and it looks like you have ordered the right convertible top set for your CMC - Or at least for a Replica.  
That’s GOOD!

But I’ll also say that I don’t know of anyone on here who has installed a SM top on a CMC.  

As a CMC builder, I can tell you that the CMC door top bolster is not drilled for the side window pegs, coming from the “Factory”.  The builder (and most CMC cars were built by people who had never built a car before) would typically figure out where the side windows needed to be, marked places on the door top bolsters that looked like they made sense to accept the side window pegs and drilled into the bolsters.  To be honest, not very many CMCs actually got the convertible top installed, many preferring to just drive on sunny days.

That means that the holes in the door bolsters are not “to a standard” and can vary in position and spacing.   A lot.   So that means that they probably will not fit any new pair of windows without futzing with something, like moving one of the mounting pegs on the windows - Maybe both, to get everything to fit properly.  

So the answer is not to go find different windows, but to potentially alter the ones you have to fit the holes yah got.  OR, drill new holes into the bolsters to fit your window pegs, fill in the old holes and apply new vinyl upholstery over the bolsters to make ‘em look good.

That’s all I’ve got….

@Gordon Nichols posted:

OK, so the good news is that you have ordered the right convertible top set for your CMC - Or at least a Replica.  
That’s GOOD!

As a CMC builder, I can tell you that the CMC door top bolster is not drilled for the side window pegs, coming from the “Factory”.  The builder (and most CMC cars were built by people who had never built a car before) would typically figure out where the side windows needed to be, marked places on the door top bolsters that looked like they made sense to accept the side window pegs and drilled into the bolsters.

That means that the holes in the door bolsters are not “to a standard” and can vary in position and spacing.   A lot.   So that means that they probably will not fit any new pair of windows without futzing with something, like moving one of the mounting pegs on the windows - Maybe both, to get everything to fit properly.  

So the answer is not to go find different windows, but to potentially alter the ones you have to fit the holes yah got.  OR, drill new holes into the bolsters to fit your window pegs, fill in the old holes and apply new vinyl upholstery over the bolsters to make ‘em look good.

That’s all I’ve got….

Thank you! I definitely figured I would just need to re-drill the holes to make the windows I have work. Im curious where I can find the Red Vinyl used to make this car, anyone have any suggestions for suppliers?

So are you saying the convertible top I have may work? I have friend/mentor coming over in a few days to help me see if we can make this top work.

Do the metal bows just mount to the fiberglass, or is there a metal reinforcement needed? Sorry for my complete lack of knowledge, here to learn!

Jack, call around. Any decent upholstery shop that’s ever done a restoration could hook you up. The place that replaced the top on my 968 would probably charge ~$1,000 to install your top.

@Jack Bolton, once again I suggest that you become a supporting member and download the CMC assembly manual. It will help with installing the top.

@Michael McKelvey posted:

@Jack Bolton, once again I suggest that you become a supporting member and download the CMC assembly manual. It will help with installing the top.

I will definitely follow this advice, thank you sir!

@Jack Bolton posted:

... Sorry for my complete lack of knowledge, here to learn!

No need to apologize as everyone on this forum was where we all are at one time.  We like having new blood and welcome the chance to show off our knowledge - or lack of same.  And if no one has said it yet, Welcome to the Madness!!!

"I'm pretty sunburnt from driving in the Hawaiian sun so much."

You poor guy lol. The CMC instructions for wiring is garbage (as is most of the manual). if everything works I'd leave it as is and just clean it up. These cars aren't driven a whole bunch nor do they really see the elements so I can't imagine the wiring is in that bad a shape. Unless the builder just hacked into a bug harness and did a half @$$ job.  I can't vouch for vintage's harness as I've never used it and  judging by their website it's a jumbled mess of wire without any instructions. You can always buy a complete bug wiring harness for your year and that would probably be the easiest way if you wanted to gut it and start all over or even do bits and pieces at a time just replacing what you already have.

On my CMC, I used the CMC wiring harness and, for the most part, followed the CMC wiring diagram.

It worked out fine for me.

@Michael McKelvey posted:

On my CMC, I used the CMC wiring harness and, for the most part, followed the CMC wiring diagram.

It worked out fine for me.

If you have CMC wiring harness I'm sure it works fine. It's just needlessly confusing imo especially if you're not running 7 gauges lol. If OP has the CMC harness I'd suggest just tracing each wire and following along on the diagram. That's the best way to learn

Welcome to the Madness, Jack!

My car started out as a homebuilt CMC. It had been assembled by a well-meaning gentleman physician who hadn't ever built a car before. Among other things I discovered, my fuel gauge indicated an increase in remaining fuel the more I drove. I also found out the steel wheel of my spare was touching both of my battery terminals, and my headlights were brighter with the switch in the off position.

That's the fun part, I guess. Learning about the car while you're sorting through the prior owners' misadventures -- and the more there were prior to you, the more varied the discoveries get.

I would add to the chorus above; downloading the CMC build manual is an excellent idea. In addition to using it as a resource, everyone who uses it to help you can do so using literally the same material you've got in your hand.

I also recommend -- if it hasn't been referenced already -- a book by the late John Muir called "How to keep your Volkswagen Alive; a Step-by-Step Guide for the Compleat (sic) Idiot."  It's as handy as a Chilton's or a Haines shop manual, but written in plain conversational English and illustrated with pen-and-ink, easily understood drawings:

https://a.co/d/iF5rjr2

I'm nowhere near as smart with stuff on my car as I want to be, and have had an enormous amount of help making it into something better than it was. There are guys on this site who've delved so deeply into these cars that they don't have to look things up, but I'm in the camp which needs reference material in order to understand what right looks like.

I would suggest putting Muir's book on the back of your toilet and taking a few minutes at a time to look through and understand how it's written ... then getting that harness together one way or another before tackling the process of replacing what's there already.

Good luck!

@Cory Drake

Remember the quote from "Tim the Tool Man":

😉

I reckon I do, Gordon. The older I get, the more instructions I can use though. Hell, I don't remember half the stuff I should about that little car in the garage.

+2 on John Muirs book. That's long been considered "the bible" for aircooled vws. A must have on any owner's bookshelf