I'm chasing electrical gremlins in my 26 trying to get it to start and I think my problem is with the switch. I have a brand new 6v battery, all new wires, new terminal block and the original mag/bat/light switch. Everything appears to be wired correctly, I have full voltage at the battery, but my coils and lights are intermittent at best and getting worse.
I took the switch apart today, sanded the swollen cardboard backing flat, lifted up the rotating leaf springs and polished all contacts. Everything checked okay when I reassembled it so I put it back in the car, checked coils and lights, shut it off to prime, back to bat and... nothing. Everything works normally if I jumper the terminal block so I'm fairly confident the switch is to blame. It might be worth noting that when I bought the car the ignition switch had been bypassed to a generic key switch under the dash
Looks to me like I have a couple options: reinstall that other key switch for now, install slightly longer screws in the switch so the contacts hit the end of them instead of those hollow rivets, buy a new back plate, or buy a whole new switch and hope for the best.
What do y'all think?
Sometimes you may have to wiggle the key a little to find the right point of contact.. If you can't adjust the leaf springs and clean the hollow rivet ends so they make good consistent contact, then another used switch may give you parts to make it work?
I used parts from about seven partial switches to make four usable ones. Repro parts are only to be used when you absolutely can't find any good old Ford parts - generally the repro switch parts may need more adjustment until they work than the old parts needs.
Thanks Roger. I tried jiggling the key and even holding my tongue just right but no joy. I'll have to keep an eye out for a replacement switch.
The last time I saw one of the $36 back plates I thought it was excellent, better than the originals, which I guess it should be for that kind of dough. Because the original switches didn't all come from the same supplier, the ones with tabs vary. If the new backing plate's tab slots don't quite line up with all the tabs, it's not difficult to widen a slot with a little grinder so it will fit.
Seems to me that I should be able to make a not-100%-correct replacement backplate easy enough. I just need to think of a good source of some kind of 1/4" sheet of insulator.
After some more head scratching I couldn't come up with any good reason why my switch would be intermittent. On a whim when I put it back in I bypassed the ammeter, hooking the solid yellow battery lead directly to the BAT terminal on the switch. Now the switch seems to be working 100% of the time. I have no idea how an ammeter works inside, all I know is mine reads about an 8 amp discharge at all times (including right now with the gauge bypassed and the battery disconnected). Could there have likely been something broken inside to cause my troubles?
It is possible for the amp meter to go bad. Inside there is a copper wire loop that makes the magnetic field to move the pointer. The ends of the copper wire are soldered to the brass posts on the back of the meter. The solder joint can crack and cause a bad connection. The fact that the meter shows something other than zero when off means there's trouble inside you need to investigate. Don't bend the loops because that's part of the calibration.