Classic/Antique Car Repair: charging system, ford fire truck, flat head v8

Question
QUESTION: I own a 1947 Ford Fire truck  powered by a 100 HP flat head V8 with a 6 volt positive ground system. I have expereinced a problem with the battery going dead and went to a distributor whon told me I had a dead cell and need a new battery in turn which I purchased. Still having problems I pulled the Generator and voltage regulator and had them tested =  both tested fine. I re-installed them when I start the truck I am showing no positive activity on the AMP gauge and as soon as I turn the head lights on I see a discharge. Can you provide me with the proper steps for Polarization and where do I look next to straighten this problem out ??

Thanks for your assistance

Steven

ANSWER: To polarize the generator remove the field "F" wire from the regulator and touch it briefly to the "B" terminal of the regulator. it should spark a bit. To test the generator for output connect a voltmeter across the battery. Then run a jumper wire from the "A" terminal of the generator to the "F" terminal of the generator and run the engine up to about 1500 RPM. The voltage should increase to about 7.5 volts or higher. If it does the generator is charging. If not the problem is probably the voltage regulator.

---------- FOLLOW-UP ----------

QUESTION: Brad

Thanks for your reply, I have followed your steps to no avail. Frankly getting just a bit frustrated, In performing a continuity test on various wires and connections I belive I may have found the culprit,however with out a wiring diagram I am not sure if I am looking in the wrong place. I disconnected the A wire on the voltage regulator and the A wire on the Generator, I was unable to read continuity across this wire. Should I be able too ? If so can I replace just this wire or do I need a whole new harness? If I need a harness and a diagram do you have any recommendations on suppliers ?? I truly appreciate and look forward to any advice you might share with me.

Sincerely

Steven

Answer
There should be continuity between both ends of the "A" wire. There should be no splices in or to this wire from the factory and you should be able to bypass it. Make sure you use 10 gage wire as the full output of the generator flows though this wire. As for a wiring diagram I have had luck with www.books4cars.com. My stock answer for where can I find….” Is to latch on to a copy of Hemmings Motor News, the old car hobbies classified bible. There are many companies that supply parts for old cars and you will find them in Hemmings. www.hemmings.com
Brad