The coil was a Bosch HEC 715. A very old Australian one. I can’t seem to find the specs so don’t know how many ohms it is. But I did think it odd that Bruce broke down a couple of weeks after fitting the new dizzy. So the ignition module could well be toast. So basically it looks like I now need a new dizzy / ignition module and a new coil. Jeez this is a nightmare. We need Bruce as our 2nd vehicle and looks like another week off the road at best.
God knows what that is. If you’re keen with a meter, you could measure the primary resistance (between +/15 and the coil lead contact).
First you need to trace and sort out all those wires before you go anywhere near a new module or you run the risk of blowing the new one.
I believe the HEC715 has 0.4 ohms resistance. Your engine has obviously been modified and the Haynes manual won’t help much when what you are looking at doesn’t look like the picture in the book. That wiring to/from the coil isn’t standard.
0.4 ohms. I’m guessing that would have caused issues with the new Pertronix SVDA distributor then. Could that have blown the ignition module or the coil or both? I’ll try and trace the wires back but it’s difficult with so many and not much ground clearance. I’m thinking though if the wiring was working before and I just replicated it on the new coil then maybe that’s not the issue?
Unlikely it damaged the coil, but will almost certainly have killed the module. What distributor did you have before? Trace your wires. You need to know what's what, rather than replicating the work of Mr Bodger.
Yeh I’ll trace the wires tomorrow. A nice Father’s Day task. I had an 009 before. So I guess I either see if that’s salvageable and revert to the old Aussie coil which still might actually be OK. Or buy a new dizzy and 3 ohm coil.
I would buy a new coil anyway. The one you’ve got is completely unsuited to life in a stock van. I’m surprised your contact breakers/condensor lasted using the Aussie thing.
If you have an 009 and a Pertronix Flamethrower coil. It will work. Pertronix coils are just expensive boring coils. Use the combo. If a coil was intended to go with the Pertronix distributor it will also work with points. Points to connect and break the current, condenser to limit points burning and coil to store energy during dwell time and release it when the points open for a spark. 50% of the high price of Pertronix is due to it being from the USA. I think the original coil worked with points because until the current gets so high the points melt, they work. Actually it says in that picture of your coil "Bosch for electronic ignition" probably meaning CDI ignition which does not store energy in the coil so does not care about the coil resistance needed to limit the current during the dwell time. All simple setups with 45 degree dwell angle have loaded up the magnetic field of the coil to saturation quite early on as the points are closed during the dwell time. As energy builds in the magnetic field in the coil, the current is limited by the coil inductance to a ramp from zero to e.g. 4 amps. For the remainder of the dwell time, the resistance of the coil (or a ballast resistor in other cars) limits the current from going up and up to stupid values. Which just would burn the points like crazy. Probably what happened with the 009 and the original coil with 0.4 ohms peak current is 30 amps !!! CDI in this case uses a high voltage inverter to store energy in a capacitor which it dumps into the coil to make a spark. Low resistance is a useful feature for CDI. Your old coil would go with an MSD 6AL CDI or similar, or a Sparkrite CDI. We call a Pertronix electronic ignition but its only one variant of a range of electronic solutions. And your strange coil is the correct one for a different solution. To me it looks like off an outboard motor !!!
Yes, as snotty says the 0.4-ohm coil would have fried the Pertronix module. You changed the coil thinking (or being told) it was faulty, then damaged it by breaking the connection. I doubt if there is anything electrically wrong with either coil but you can’t use the Bosch because the resistance is too low and you can’t use the Pertronix because you’ve broken it. A 009 is not the correct distributor for your engine, all you need is a new module for whatever model Pertronix distributor you have and a normal 3-ohm coil. https://www.ebay.co.uk/itm/360651813520
Bosch do appear to still make them. I assume they’re intended for systems controlled by an ECU that can tightly control the dwell time.
New dizzy and coil arrived today and I fitted them and got Bruce running again. I timed him to about 28 but he’s a little uneven on idle and idling slightly fast but just very pleased I’ve got him going again. Maybe he needs a bit more timing? Any ideas what this was? (in the photo). The old coil was wired into it.
Electronic ignition module, which would explain the fancy coil. Likely still works. 28 degrees is fine. Use the idle adjustment on the carb to adjust idle, not ignition timing!
Has it got a Bosch part number on it, out of interest? Looks like an external module from maybe the 80s.
Looks very Lumenition-esque so it could be the brains of an optical ignition system ? These were state of the art in the early eighties Sent from my SM-G960F using Tapatalk
Maybe, but looks like a standard late 80s Bosch external module. Used to either lash them to the bodywork or later to the side of the dissy. When full engine management came in, nobody used them any more: no need. Do much the same as a Pertronix module, but bigger (and more reliable).
