What's the difference in ignition modules?
 

I'm on LMC truck looking at ignition modules, and they have different modules for different years. They have a 1974, 1975, 1976-77, and 1978-79 module. What's the difference between each one and does one have an advantage over the others?

My truck is a 75, the motor is a 460 out of an 88. I'm completely redoing all the wiring and ignition, so any wiring issues that would keep me from using a certain year wouldn't be a problem.

Jared

Hi Jared - welcome to FTE! Match the colour of the plastic grommet the wires pass through coming out of the ICM. I have seen black, blue and green. I have tried different colour ones and the truck wouldn't start. Hope this helps.

Thank you sir! Sounds good. I'll have to dig through my junk that came with the truck to see if the old one is in there.

Exactly! Myself, I wouldn't trust LMC truck.....go to your local parts store and pick up a Motorcraft brain box.

https://www.ford-trucks.com/forums/a...2&d=1328618683

I switched from a 75 to a 79 module. There are more RUN and ACC leads to tap into. Since you are re-wiring, this makes it better IMO because one wire will not carry the whole load to the harness.

Awesome! I might go the route then. Yeah, I'm doing a frame up on my crew. All the wires are old and oily so I'm just gonna redo the whole thing.

Will you show pics of your engine?

According to "the man":
Ignition modules, 74 (black grommet) and 75 (green grommet) are year specific and will not interchange. 76 to 79 (blue grommet) are interchangeable.
Ignition modules: 1974 is 1974 ONLY / 1975 is 1975 ONLY.
Blue module introduced in 1976 was used well into the 1990's.
D4AZ-12A199-C 1974 only
DuraSpark ignition modules identified by a colored plastic insert located above where the wires feed out.
2 others: One has a*red*plastic insert, the other has a*yellow*or*brown*plastic insert.
Red*module is*D7AZ-12A199-A*used in some CA vehicles ONLY.
D9AZ-12A199-C*(replaced D8AZ-12A199-A). One of these modules is*yellow , one is*brown*.. Since the part number was replaced, I cannot recall which module was which color.
These modules were used in 1978/79 302 & 351M/W vehicles sold in high altitudes only. 351W: Passenger Cars & Econolines only.
1U2Z-12A199-AA*(replaced D6AZ-12A199-B - D7AZ-12A199-B - D8VZ-12A199-A - D9VZ-12A199-A) .. Ignition Module -*blue*insert (Motorcraft*DY-893) / Available from Ford.
Myriad 1976/90's FoMoCo vehicles.
Green Sales in OH.
Collectors Auto Supply in WA.
Haven Ford in KS.
Klimesh Motor Sales in IA.
Bob Allen Ford in KS.
Freese Motor Inc in IA.
Wesley Obsolete Parts in KY.
Dennis Carpenter Ford in NC.

Oh Boy. Pardon me. I thought he was speaking about the ignition module as in where the key goes. My bad.

That is an ignition "switch" then. 73-77 is a smaller connector with less wiring, 78/79 is a bigger connector and has a few more wires.

It's all good. I meant the module, not the switch. But I'll definitely keep what you said in mind when I go to get a new switch.

Ignition switch is what the electrical connection connects to behind the dash. The key actually goes in the lock tumbler, at least that is what I call it.

And that is removable without removing the switch from the dash. But you do need the original working key and a paper clip.

I've been through 3 from oreilly auto , they can test them , finally went with Napa Auto and haven't had a problem . They cost about $70 , good luck with the build .

if i remember correctly rockauto.com has the motorcraft ones for @$40.

I'm curious if aftermarket modules use the same color grommets to identify them. I go to lots of parts swaps & find new ones in the box, but never knew how to ID them, as they all have their own part # on them. If the aftermarket has the colored grommets, I'll pick a few up as spares. Often they are really cheap, & are made in the USA, not communist China.