I have been reading recent magneto problem threads with great interest as I am at the point I have to try to get mine working. I did not want to hijack Wes's thread especially since mine is somewhat different.
Using John Regans 1156 bulb test, today we tried it out. The bulb lit up at idle but output was only 4 volts at a "brisk idle" it went to 5 and at high speed it went to 6. I turned the switch from Battery to magneto and the motor backfired twice and died. I tried that twice with the same results. So far I have not removed the post to clean it as recommended - before I do that I wanted to ask if there are any precautions I should be aware of. Incidentally, I have new wiring installed per John Regans diagram - also a new (aftermarket) switch. I have noted the switch does not work if turned all the way to the left - it has to be backed up slightly to make contact.
My T is also a 26/27 and it runs great on battery. I would like to get the magneto working as that is a major part of the car's lore.
Looking for advice, recommendations, further tests please.
The backfireing was probably due to a switch going bad or defective.Both of mine are giveing trouble,thus both of my mufflers look akin to a califlower.
I would read up on chargeing the magnets first with 36 volts and a compass.Then look up the info on the man that rebuilds switchs.I aint tried it yet myself but will try some contact clean on 1 of mine.The reproduction switchs are of poor quality.Have a orignal rebuilt.It aint cheap but the switch works better. .
James:
It is highly unlikely that cleaning the mag post will give you even a single volt more mag voltage let alone the additional 20 or more volts that you need - still - it is worth a try. Assuming your car has a 26/27 motor in it then the mag post just unscrews out of the hogshead (transmission bell housing) so unscrew it, clean it off, and put it back. Repeat the 1156 mag test and when that is still low you need to then bone up on doing an in-the-car magneto recharge. I recommend this only when you have nothing to lose by trying it and that is the case if your mag voltage is as low as you have reported. Do check your AC volt meter if possible to make sure your meter is not fooling you by being totally inaccurate on that scale of your test meter. I am assuming you did not try the test using a digital meter. If you did use a digital meter then disregard all of the above advise and start over using an analog meter.
I used the 5012C switch repair kit sold by Lang's and the quality is fine, BUT you may have to adapt it to fit. Because Ford used more than one supplier, the switches don't all have the clips in exactly the same places. No problem. Just use a little grinder and widen one or two of the notches to match the clips. Actually, the material used in the repair kits is better than the original cardboard.
I had a bad switch on my 26 that shorted out the magneto. The car would not run at idle but would run at a fast idle on magneto, giving about 18 volts max. One day, after several tries working the switch to back to magneto, the magneto
quit entirely. I tried several different things with it and was unsuccessful with trying an "in the car" magneto charge as the compass wouldn't move with cranking the car. I sent the switch off for repair and pulled the engine. I replaced the magneto with one of Wally's and recharged the magnets off the flywheel. None were broken and the magneto looked OK to me. I think the bad switch shorted to the magneto demagnetised the magnets. The back of the switch was toast, with a contact burned out of the fiber backing. It runs well now.
Here is a post from 2010 documenting the valuable advice I was given by the good folks here and my experience, in recharging my magnets, using three 12V batteries while I was overhauling the engine with the engine out of the car and on the engine stand, with the hogshead was off. www.mtfca.com/discus/messages/118802/159978.html.
I did have installed, a rebuilt "Total Recoil" magneto by Wally and I had the magneto coil to magnet gap perfectly spaced, but my magnets were too weak for them to even cause the needle on the compass to move which is why I had to manually locate the N magnet with the hogshead off. And while I was at it, I scribed the (4) 90 degree N magnet positions, I used, on the crankshaft pulley for future reference in case the magnets ever need to be recharged.
Long story short, it worked like a charm and my magneto remains so strong that I can easily start my '26 coupe on MAG. Jim Patrick