ICM and Ignition Coil keep burning up
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ICM and Ignition Coil keep burning up
I have a 1984 F-150 4X4 with the 300 I-6. It has a 4 speed manual transmission. Okay so here's the problem... my truck keeps burning up the ICM and Ignition coil. Ive replaced both of them twice within a one week period and they both burned up in less than 20 minutes of driving leaving me stranded. Ive had people tell me that it is grounding out but i have searched the truck and cant seem to find any bad grounds. Could a resistor be bad? any help is appreciated. (this truck has headers and a 4v Carb intake).
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Thanks. I am the only owner of the truck and have never modified any of the electrical wiring. Could it be a possibility that the resistor is wore out because its never been replaced and where would it be located at? Also, would you happen to know where the EEC is located?
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From: Virginia
I have a hard time nailing down when they did, and did not use electronic engine controls on some of these engines. Does your distributor have a vacuum line going to it? What does the underhood sticker say(EECIII, EECIV)?
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Yes i am using the electrical grease that comes with ICM. According to the haynes manual...it says that there is a resistor (84 f15o with 300) on one of the wires that leads to the EEC from the ICM. It is associated with the ignition coil.
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Cargo Master
Joined: Mar 2008
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From: Washington
Napa has "heat sink compound" which is the best. It is white in color. I would not risk using the di-electric grease as it does NEED to have a good way to dissipate the heat. The old one most likey failed due to the lack of a good way to remove the heat from the module.
more info here.
https://www.ford-trucks.com/forums/7...on-module.html
more info here.
https://www.ford-trucks.com/forums/7...on-module.html
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i dont think that the grease is causing the problem...i get my parts from carquest which are generally very good products. Im leaning more towards a bad resistor or bad wire. does anyone know where the ECC (computer) is located on a 84 f-150 with the 300 staight six?
Cargo Master
Joined: Mar 2008
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From: Washington
The EEC IV uses full voltage to your coil, so if your ALT is putting out 14.5 volts that is what is going to the square coil... you do have a square coil and NOT a round one????
The resistor wire is still in your trucks wiring harness it is just not being used to feed the coil.
Cargo Master
Joined: Mar 2008
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From: Washington
The part of this that does not make sense to me is the square coil failing also. How do you know the coil is failing? Did you have it tested at the auto parts store? Are you just changing both the coil and the ICM at the same time just to get the truck to run?
I bought a new duraspark distributor on Ebay for $50 from this guy. Item number: 370100430475<o
></o>I really don’t recommend putting money into trying to fix an EEC IV system. For under a $100 you can get rid of the EEC IV and use a Duraspark vacuum advance distributor with a different ignition module. I was running my 86 F-150 I6 for years in a fixed timing mode (EEC IV) without ANY ignition advance and never did know it wasn’t working correctly. It seemed to run fine at the time… but it was losing MPG and engine power. After getting rid of the EEC IV my MPG went up 3 or so but the increase in engine power was really noticeable and I am currently still using the same feedback carb you have on your truck.
Search duraspark, DS2, DSII for more info on converting. I think your 1984 I6 could have had DS2 or EEC IV ignition… depending on what month it left the factory.
Photo of my carb is here.
https://www.ford-trucks.com/forums/745319-carb-p-n-year-id-help-needed.html
Info on testing to see if your coil is good here and also info on getting rid of the EEC IV.
https://www.ford-trucks.com/forums/750740-coil-problems-i-think.html
Jim
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Well...ive decided to rid the truck of using any of the computer. Im going with the Mallory Uni-lite optical distributor. Im tired of fooling with the EEC-IV and personally, i believe the main cause is faulty wires that lead to the ICM in which i cant blame the truck, its 24 years old, wires get old and deterioate. WIth the new distributor, i will be able to run 3 wires, one hot, one to ignition, and one to the coil. There really is no purpose for the computer on this truck, all emmisions have been removed. I blame Ford for horribly designing the EEC-IV system, since the truck was bought in 84, it never ran "right" because of the computer. There were always carbuerator problems and i am not the only person complaining of this.
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From: Virginia
They worked good when new, but I agree when it gets old, there are too many things to go wrong, and the parts are too expensive. I believe a lot of these trucks would pollute less, by converting them over like you are going to do, instead of trying to run the old system that doesn't half work.
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Well...ive decided to rid the truck of using any of the computer. Im going with the Mallory Uni-lite optical distributor. Im tired of fooling with the EEC-IV and personally, i believe the main cause is faulty wires that lead to the ICM in which i cant blame the truck, its 24 years old, wires get old and deterioate. WIth the new distributor, i will be able to run 3 wires, one hot, one to ignition, and one to the coil. There really is no purpose for the computer on this truck, all emmisions have been removed. I blame Ford for horribly designing the EEC-IV system, since the truck was bought in 84, it never ran "right" because of the computer. There were always carbuerator problems and i am not the only person complaining of this.