1985 F250 EEC IV ADVICE NEEDED
Thread Starter
|
Senior User
Joined: Feb 2011
Posts: 291
Likes: 3
From: Crossville, Tennessee
1985 F250 EEC IV ADVICE NEEDED
I am working on my friends 1985 F250 4x4 4.9L straight six. it died on him while driving. He put a new ignition control module on the distributor. It started and run for a few seconds, he turned it off and it hasn't started since. So he asked me to fix it. Not my specialty but I like a challenge right.I have verified no spark from coil.
I have 12v at the coil.
I have no grounding signal at the coil other wire.
I have no ground at the black (bottom) wire of the ICM with key on or off.
I traced that black wire to the EEC IV module where I unplugged the connector and have excellent continuity.
At this point I am assuming that the EEC IV module has control of that wire, making the ground through EEC. In which case I suspect faulty EEC module.
Does anyone know, am I on the right track here? I really don't want to waste money on parts that I have diagnosed incorrectly.
thanks in advance
Moderator
Joined: Jan 2001
Posts: 56,990
Likes: 2,740
From: Virginia
You are on the right track. But usually the EEC doesn't "generate" a ground, it gets a ground from a ground wire going to the large wiring plug to the EEC. My diagrams show the ground wires for the EEC are near the end of the plug. One of them is a black/green and the other a orange? wire right next to it. See if these are properly grounded.
Thread Starter
|
Senior User
Joined: Feb 2011
Posts: 291
Likes: 3
From: Crossville, Tennessee
The black /green from EEC runs to the battery neg post. I checked it and it is good.
The ignition ground wire on the ICM ( the bottom wire) has no ground at ICM. I traced it back to the EEC where I disconnected it and that same wire has continuity to there.
That is what got me thinking that the EEC controls that ground.
this system has always confused me lol
The ignition ground wire on the ICM ( the bottom wire) has no ground at ICM. I traced it back to the EEC where I disconnected it and that same wire has continuity to there.
That is what got me thinking that the EEC controls that ground.
this system has always confused me lol
Moderator
Joined: Jan 2001
Posts: 56,990
Likes: 2,740
From: Virginia
Well, I guess a trace could have burnt up in the EEC. What would happen if you grounded that wire yourself at a convenient spot under the hood(to the engine block). I would leave it hooked to the ignition module of course, and leave it hooked up to the EEC in case the EEC would like to use that ground for something. It would be worth a try I think.
I guess you know you can ditch this whole system if you like and put a older type dist in it. Is everything hooked up and working or are a lot of vacuum lines and other gizmos disconnected under the hood?
I guess you know you can ditch this whole system if you like and put a older type dist in it. Is everything hooked up and working or are a lot of vacuum lines and other gizmos disconnected under the hood?
Thread Starter
|
Senior User
Joined: Feb 2011
Posts: 291
Likes: 3
From: Crossville, Tennessee
I may try adding ground there and see if it works. It is pretty well all still intact under the hood. Usually wires and hoses have been butchered by now, but this guy is particular with this one.
Thread
Thread Starter
Forum
Replies
Last Post
wantaford
1967 - 1972 F-100 & Larger F-Series Trucks
13
Apr 2, 2006 03:25 AM
mamafedmepaintchips
1967 - 1972 F-100 & Larger F-Series Trucks
12
Nov 27, 2003 01:25 AM
