Hi Guys, going through the basics after installing my new engine and can’t get it to start. It’s got fuel and it ran on the bench. Which is leading me to question wiring. I’ve got black wire from the dizzy to the negative on the coil. Then positive red to carb solenoid and choke. Red positive to dizzy and a black wire from the main loom to positive on the coil. I have an unexplained red and white wire pictured from the main loom which may be lighting. And I have a large red/white from the alternator to the main loom. There’s also a small black wire which I assume is earth. Could anyone confirm if this is wired up right? It’s a 73 bay 1600 Will post some pics shortly
Black and red wires from dizzy sounds like electronic ignition?.. Sounds about right.. Black from the main loom (ignition) to the + coil then that goes red dizzy and whatever to carbs. Black (oops two reds there...) dizzy to negative and that should be enough. Are you gettng any spark?. Is there 12v at the coil? We're the wires wrong at any stage.. that red black swap to dizzy is a real electronic ignition killer... Sent from my SM-G930F using Tapatalk
Hi there yes it is electronic ignition. Apologies should have mentioned that. Yes I’ve currently got black going to the positive on the coil from dizzy and red from dizzy to negative and haven’t swapped them. I’ve not been able to test voltages as yet as can’t find my test light :/
The red on the dizzy should go to + on the coil The black on the dizzy should go to - on the coil If it is the other way round you have probably fried your electronic ignition module. The + on the coil is normally fed by a black wire that isnt normally fused !
The damage happens in milliseconds as you connect any power to the electronic unit, it fires the coil once. Which if you have black to black pops the switch transistor immediately. I also believe that there is one factory somewhere that makes exactly two kinds of module, and everybody badge engineers them. One old one, and one with adaptive dwell. The circuit board inside is made with a fairly high technology process, a thick film hybrid, not some random FR-4 . The fact they all blow up the same way also leads me to believe there is a single manufacturer.. It would be possible to add a few parts to create a lockout that prevented self destruct. But this would reduce sales by at least 50% as everybody who uses them blows up a module because of those confusing wire colours .... One of my pastimes is trying to sketch out the schematic of the unit I stripped down and scratched off the potting compound.
Practically, you can’t. If the wiring’s connected correctly and no sparks are being generated, it’s dead.
But if You do need a moving distributor rotor for the adaptive dwell versions to switch the current in the coil. The earlier versions are just like points in that every 90 degrees of rotation of the distributor, the coil output is on for 45 degrees then for 45 degrees it is turned off. But in general once you are not getting life from an electronic module, its another £40-£80 depending on the brand sticker you are paying for, to get a new one.
Just been out to double check I’ve got black dizzy to negative Coil and red dizzy to positive coil. I had TB e thick black wire from the loom to the negative side of the coil which I’m assuming is power. Will this have the same effect of frying the module?
Probably yes I'm afraid.. as the thick black loom wire is positive and that'll go to the dissy the wrong way.. I did a similar thing by sending a positive down the tach wire from the dash!.. Sent from my SM-G930F using Tapatalk
Doh! You live and you learn. Can’t even blame colour blindness for that one! thanks for your help guys I’ll get one on order and keep you posted
Yes exactly the same, sorry . The coil doesnt really care which side is positive or negative, only in high performance engines will there be a difference. The damage is done by the black wire from the module being connected to 12 volts through less than about 3 ohms DC resistance, or more than about 4 or 5 amps flowing..in less time than it takes for the key to click..
