[TR] Ignition coil question..

[Dave Connitt]

Hi List,
Like practically everyone on this list, my garage is way too cold to venture into for at least a couple of months so.. Here I sit writing this email.
Today I discovered a bunch of old Classic Auto Restorer magazines from back in the late '90's. Besides the date on the cover, there are no references to email or website addresses which is kind of wierd. 
Anyway, I was re-reading an article explaining breaker point ignition fundamentals and troubleshooting. The writer made some interesting points ( sorry for the pun) regarding reasons a coil may die.The writer states that there are two main causes of coil failure, moisture entering the coil and heat. The moisture will usually enter the coil at the seal between the case and the top. Usually caused by corrosion at the joint. Heat is another matter, This is usually the result of a voltage higher than 8 VDC in a 12 volt system. The writer stated that a resistor in series with the ignition switch in the "ON" position will allow the full battery voltage (usually slightly more than 12V) during start only. Once the engine startes and the ignition switch Triumphs have the coil mounted to the side of the block! Short of the exhaust manifold, I can't think of any place hotter to mount the coil.
Well, it was an interesting article.. Wait, the Top Gear episode where the boys travel from Florida to New Orleans and practially get killed after painting slogans offensive to southerners on their cars!!!
Dave Connitt
'67 TR4A IRS
http://home.fuse.net/davestr4a