MTFCA Forum

Steve,
Thanks so much for the photos and explanation, it is very much appreciated.
I am going to measure the mag resistance cold, and then when it is hot and "failing" to see if I can detect a short.
Still amazes me that the problem is so predictable and consistent.

Curt

R.V. - thanks for your reply.

I am not following your explanation (I am not well versed in the details of the mag and terminology. Can you explain further?

Thanks,

Curt

Steve, Thanks for your input. Yes, I am checking the voltage at the mag post with an analog meter. The difficulty in troubleshooting this issue is that it only occurs when hot, so there is limited time for diagnostics. I have found a couple of items that I thought could be the issue, but it takes 1/...

Sixteen million cars and 100 years - somebody must have experienced this before and have specific info. I am trying to avoid changing the mag only to find out that it is not the issue.

Any specific suggestions for troubleshooting would be much appreciated!

Thanks,

Curt

Thanks B_Zero_B, This has been occurring for some time (500 miles). It goes from running perfectly on the mag to shutting down. I would have thought that if it was shorting out due to thermal growth at some point it would stay shorted as the insulation is further damaged. I don't know if the mag is ...

Working on a 1925. Magneto works fine when the engine is cold and puts out 25 volts. After about a half hour of driving it stops working properly and drops down to about eight volts and will only run on battery. Once the engine cools down, voltage is back up. Has anybody experienced this problem? An...