Ignition Module differences

[djohnston89]

I fried my newly acquired 87 Eagle's original ICM trying to start it for the first time in years and years (more details on my thread in the project cars section). When I went to replace the module, I found that the connectors  on the replacement ICM didn't match what was in my car so I asked for the unit out of an 88 Wrangler with the 258 which ended up having the correct connectors. I later found that parts suppliers who have the 88 Eagle in their computer, also specify the kind of module that I have (the 88, however, was not in Advance Auto's computer for some reason).  Both modules have the same color wires, and blue strain relief, the only difference aesthetically is the type of connector.

The other difference in the two modules, is the price. For some reason the type with the new connectors like mine run around $70-80, whereas I've seen the type with the older ones listed as a cheap $20. So my question is: If I need to replace my ICM again, can I just lop the connectors off the one I have currently and splice them on to one of the older style ICM's?

[carnuck]

You can find the older connector on a Ford, Jeep or Eagle and splice it to your harness to run the older box. Many guys on the Full Size Jeep list have done this. Just make sure you have a good ground from the box to the distributor because one of the "upgrades" the new harness has is a thicker ground wire so if the engine to battery negative cable is loose, the wiring to the dist doesn't go up in smoke and eat boxes.

The other option is a Jeep converted GM HEI distributor (like the Skip White unit I got) and do away with the fender mounted box and the coil with crappy horseshoe connectors that corrode and cause stalling/misfires and have 1/2 the spark. It allows you to run upgraded plugwires too. Then it's a 1 wire to run, should something go wrong in the middle of nowhere.

[eaglefreek]

After my 20+ year old ICM went out, I replaced it with one from an auto parts chain. It only lasted 6 months. I installed a MSD Streetfire CDI and haven't had an issue in the 4 years it's been on.

[IowaEagle]

Yes the ones with the weather pak connectors do cost more.  Why I don't know.

[carnuck]

I replaced the Motorcrap dist with an HEI in '97 and haven't touched it since in my '84 J10 other than to swap it from the 4.2L to the 4.0L I put in.