Working on an 85 bronco, 300-6, 4 spd, converted to DS2 ignition. I did the ignition swap a couple months ago, and it has ran fine until now. All components were new at the time of the swap. All components HAVE been checked out and are good, including the coil, dist, pickup coil, and harness. I have no spark whatsoever, and it immediately fries the ignition control module the second you turn the key on, (for all I know it fries out the second you plug it in). Wherever the problem is, it is before the plugs to hook it all into the system, in other words, it is in the truck's harness. Everything from the plugs out has been checked many times over, isolated and rechecked many times over. The harness for the ICM, coil, pickup, and dist. has been checked for shorts, resistance and continuity many times over. I even broke down and spent the $10 for a new ignition switch. We now have the entire dash out of the truck, all wiring checked working our way backwards through the system. Still- fries out the module and no spark. I posted this in the bronco section, as I have been going through all the checks today, and decided to repost it in here so more people can see this-the more ideas the better- I am at a complete loss. Thanks to whoever decides to give this a shot!

 

How do you know it fries the module? Are you taking to the store afterward and they say it's bad?

I would unplug the coil, but plug everything else in, and turn the key and see if it fries the module. Of course it won't run this way, but it would isolate the problem. You may also want to take the battery cables off, and hook a small battery charger to the cables, and see if the circuit breaker will protect the module till you get it figured out. It may or may not catch it in time to save the module.

 

Yes- the module is checked straight out of the box at the store. I bring it home and plug it in, and no spark. Go straight back up to the store and test it, it is bad. I am fortunate enough to have a really good friend who is the manager of an auto parts store, I even check them out myself on their equipment. It has fried 3 in 2 days. He has even come over after work for a few hours to try to help me find the problem.