I have tried everything!!! and can't determine what is causing my module to fail supposedly from heat, they are supposed to be designed to withstand that however since they are shoved into the side of the camcover.   It has to be that something was done to the electrial to cause it to happen to my 03' XLH1200.  Anyone out there with a clue

Be a bit clearer with what is actually happening mate, stuff like.....

ignition comes on but wont crank over...

engine cranks but wont fire up...

put down exactly what is happening (or not happening).....

It will certainly help us to help you with more info.....

How do you know it's the ignition system causing the problem? Could be a LOT of things other than the ignition system my friend, do as Jetman suggested and give us the symptoms so we can attempt to help you nail down the cause of the problem.

If it is heat taking it out, it could be you are not using Dielectric grease on the mounting surface to transfer the heat away from the module.

Sounds bogus all the way around to me.

First sentence just dont add up...

It burn out coils every couple months and always on the back cylinder.. then the module starts acting up... when it get warm it dies and as soon as it cools it starts...as long as I leave the cover off it works OK... it gets plenty of gas carb is stock and rejetted... before it dies it usually backfires.. timing is dead nuts right on.. battery is brand new.. rectifier is brand new.. coil is brand new.. module is brand new.. plugs are fine.. plug wires are brand new.. the carb is not sucking air,, there are no vac leaks.. smog is gone with high intake backplate and DS element.. all sensors have been checked by Harley Fresno and Visalia and OK as well as all the other stuff just put on. I have been told it is vapor lock by at least one person which seems unlikely since it is the original carberator that was reworked in 04 and has done just fine. I just put another module in it after going through everything else.. within a month it starts acting up again.

everything does come on... it will crank over... it will not start once it dies until it cools down... even at 70 mph. It is not the kill switch.. or the wires... not the ignition switch or the wires.. not the sensors or the wires

appreciate the comeback you guys...

Your kidding right?

You say the plug wires are new? Are they the correct wires? Copper core or silicon? There are many variables at play here, could be you have bare wires touching somewhere creating the "heat" related symptoms. Are you sure it is ignition? Circuit breakers act the same way. They get hot break, cool off and reset themselves. What was the last thing done to tthe bike just prior to these problems occuring? That may be the culprit.

You also say you have replaced the coil? Is it compatible with the ignition system (proper ohms)? Are you painting the coil or does it have a cover? Some paints will "bleed" through the housing and act as a conductor and short out the coils. I ran into this while building a custom bike. The customer was bound and determined that the coils MUST be painted to match the custom paint job. It took a few months to figure it out.

I had the same problem with a 1999 Electraglide. I was celebrating personally (on the bike), smiled inside, that we'd just ridden 50K miles together when she quit. It was eerie. After sitting for awhile it would start up again and I'd get about 35 miles down the road and it would quit again. I limped, 35 miles at a time, back home. At first I thought it was the fuel pump but I quickly learned that there's a very slim chance that the pump would fail. It turned out to be the ignition module itself and I never had any problems after that during the course of the next 30k miles we shared together.

Well, I had the same situation on an older bike. It could be that there is a wire shorting out intermittently, and those things are usually in the most undiscoverable location on the bike.
A spilit-second short caused by melted insulation, or whatever, will fry that module right now!
Rather than re-wiring the whole bike, you can put an additional 15 amp circuit breaker (use the rectangular tin-can one) directly in line with the feed to the ignition module. That way, when the short hits, the breaker will trip briefly, then you'll continue down the road. You may not even notice that it tripped. Just goes back to work. Thing is, when this method works, and you ride for a few months with no problem, you'll have your diagnosis, and you'll have spent, like, 5 bucks and 30 minutes getting it.
Then you can decide whether to re-wire the bike, or stay happy with it and ride. (That's what I did - never another problem.)

No paint..... no cover..

The bike has gone through two HD shops and I have spent countless hours chasing theory... I have been told it was vapor lock and that I didnt use dielectric grease under the module plate... after talking to two mechanics they also concured the grease is nessesary.. I also took off the aluminum cam cover and put a chrome one on w/ the 100 yr emblem.. this also increased the heat level.  Nobody at HD could find a thing wrong with it but it gave me trouble for years and then finally failed.  So I replaced everything but the tilt sensor and light module bolted to the rear fender.

I had just replaced the module when it failed again

I am going to put the aluminum camcover back on use the dielectric grease and try your fix for both the coil and the Ignition with a  2.5 amp fuse... thanx Bofas.. I realy love my Sporty.. If I rode a bigger bike it would have to be a big long fat monster custom to keep me happy.  W/ a Hunter Mag and no damn battery.  thanx for the comback Bofas.. I appreciate sound logic