Picked up another old caddy, this one a 47 that ran at some point in the last year but not now. 6v negative ground system, problem is no spark. Just put in a 6v fresh battery. The ignition coil only has one terminal labeled "dist" which has a single wire to the distributor, and it looks like the coil case is grounded to the firewall with the mounting bracket. No spark out of the coil. I cleaned the points and then put a test light on the DIST terminal on the coil and the light flashes while cranking the engine, so I would think the points would be working. I want to try another coil, and have one on hand that measures 1.2 ohm across the primary, so I think I can use it even though it was in a 12v car with a ballast resistor. Maybe a dumb question, but since my spare coil has + and - terminals, do I connect the wire coming out of the distributor to the + of the coil and jumper the - of the coil to the car body? Or vice versa? Never seen an ignition coil with only one terminal, but I am assuming the metal case is the ground. Too many years away from points, need a refresher! TIA
Connect the wire coming off your ignition switch to the original coil, to the new coil positive terminal. Connect the negative terminal on the coil to the wire leading to the points. Don't use the ballast resistor.
got it, connected the points to the - side of the coil and ran a jumper wire from the + to the battery. What was throwing me off is I could not find the + feed to the coil, then I saw that it has one of the coils with the armor cable that goes to the ignition switch. I have never had one that worked, so never had to troubleshoot one, and totally forgot about that thing. Does anyone know how they work? Is it a mechanical connection from the key switch to the bottom of the coil or is there wiring inside?
The armor is to shield the ignition wire from RFI, in an attempt to keep the radio from receiving ignition induced static. One end of it should be connected to ground.
Before you get too carried away, are the points opening and closing correctly? Simply meaning, you have no idea of what someone else tried before the car sat before you got it. I've looked at a number of rigs in the past 60 years that someone set the point gap with the rubbing block of the points on the flat of the distributor cam rather than the tip of one of the lobes and the points get wider but never close and your test light shows power to the coil as the test light is completing the primary circuit.
I believe that they were called an Electrolock, to help prevent auto thefts....here is a closer view.. as well a link to lots of photos of it... 1940's CHEVY PONTIAC DELCO IGNITION SWITCH CABLE WITH KEY electrolock electro | eBay
Thanks, I put a test light on the coil to distributor wire and it flashed as the engine cranked, so points looked to be working ok.
Awesome, thank you! Maybe the coil is ok and it is just a dirty connection or something, would be nice to get it working.
Strange how that electrolock system was supposed to work- any self-respecting car thief would get past that with a piece of wire and a hammer. Especially when most were stomp-starters too!
You say you need a refresher course on points ignition systems? https://www.jalopyjournal.com/forum/threads/hot-rod-technical-library-basic-ignition-systems.983424/
The Jalopy Journal
