I'm not sure about the 73's but on my 76, the blower motor is always on. It does allow me to go from low to high and when turned to high, it goes through a relay on the dash. I read where the blower always being on is for the flow through ventilation. Hope you find the problem soon, sounds like your'e on the right track.

Thanks guys. I made it back home and now I will be looking into the issue further. I am not against using a band aid when it is called for but I always go back and fix it the correct way as soon as possible. I will keep you up to date when I have my findings.

ALL A/C cars have the blower set-up like this. Non-A/C cars do not....they have an "Off" position, with Lo/Med/Hi fan speeds. A/C cars have low/low-med/med/hi fan speeds. It is in fact for air circulation.

Glad ya made it home safely Brian.

OK I have an update finely. Sunday I had the chance to get back on finding the problem. I purchased the electrical prints from Dr. Rebuild,. They have a lot more details then the one I had from Lectric Limited. Any way, between the two I was able to piece it all together. To start with, from the factory the power comes from the battery to the starter. There a 12 gauge wire travels to a 14 gauge fusible link wire and then connects to a 10 gauge wire that travels to the horn relay. From there all the wires have fuse links and travel to what ever system they need to power. The alternator has a 10 gauge wire that also travels to the same horn relay. This wire is not fused. My best conclusion for this is this; If you had to run everything off the battery connection the 14 gauge fuse link wire would not be able to handle the load by itself. That is where the alternator kicks in and does most of the work. Now to my issue. A while back I added electric fans and a new 100 amp alternator to handle the new load. When I did this I disconnected the original alternator wire and ran a new wire back to the starter. This new larger 8 gauge wire also carried the power to the new fans. That by it self was not the problem. The problem came when I disconnected the old wire from the alternator to the horn relay. With this I caused the system to rely on the old wire coming from the starter to the horn relay. Over time it caused the 14 gauge fuse link to blow. I was lucky it lasted as long as it did. Anyway, everything is good now and I hope some one else can learn from my experience.

Nice job,