86 Ram Coil questions
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Joined: Jun 2005
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86 Ram Coil questions
I have an 86 Ram with a 360, Edelbrock Performer Intake and Carb. Its a new long block with about 1500 miles on the rebuild. Most everything is new that can be.
According to my manual, it says with the key in the ON position, the voltage on the coil should only be 1 volt less than what is at the battery. Mine is half. If i disconnect the negative side of the coil, the voltage jumps up to where it should be. Also, if i leave the negative on the coil and then disconnect the ECU, the voltage again goes up to where it should be. I have looked and looked and dont know what I am missing. The truck will start with the voltage at 6.7v at the coil. Its alot harder to start after its hot though.
I have put on a new ECU, starter relay, ballast resistor and checked the resistance on the coil.
Does anyone have any idea why the voltage is so low at the coil?
According to my manual, it says with the key in the ON position, the voltage on the coil should only be 1 volt less than what is at the battery. Mine is half. If i disconnect the negative side of the coil, the voltage jumps up to where it should be. Also, if i leave the negative on the coil and then disconnect the ECU, the voltage again goes up to where it should be. I have looked and looked and dont know what I am missing. The truck will start with the voltage at 6.7v at the coil. Its alot harder to start after its hot though.
I have put on a new ECU, starter relay, ballast resistor and checked the resistance on the coil.
Does anyone have any idea why the voltage is so low at the coil?
Joined: Jun 2005
Posts: 21
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RE: 86 Ram Coil questions
Are your wires origional or new? If they are origional, it could be just bad wires, and they need to be replaced, otherwhise, i dont understand, it kindof sounds like you might have a short somewhere, but since it does it on both wires, that wouldn't make sense.
Joined: Jul 2005
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From:
RE: 86 Ram Coil questions
Sounds to me like you have a bad coil. I too have an 86 Royal 4X4, 360 and just put in a rebuilt engine(built by me). I had to replace my coil as they do sometimes go bad even though the resistance reads good. You could have possibly lost some oil out of it. A coil is basically a transformer and it will not work right if the oil is low. I'm also an electrician so I understand automotive electrical systems. If I can help let me know.
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Captain
Joined: Sep 2005
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From: Colorado
RE: 86 Ram Coil questions
ORIGINAL: 86RamRoyalSE
I have an 86 Ram with a 360, Edelbrock Performer Intake and Carb. Its a new long block with about 1500 miles on the rebuild. Most everything is new that can be.
According to my manual, it says with the key in the ON position, the voltage on the coil should only be 1 volt less than what is at the battery. Mine is half. If i disconnect the negative side of the coil, the voltage jumps up to where it should be. Also, if i leave the negative on the coil and then disconnect the ECU, the voltage again goes up to where it should be. I have looked and looked and dont know what I am missing. The truck will start with the voltage at 6.7v at the coil. Its alot harder to start after its hot though.
I have put on a new ECU, starter relay, ballast resistor and checked the resistance on the coil.
Does anyone have any idea why the voltage is so low at the coil?
I have an 86 Ram with a 360, Edelbrock Performer Intake and Carb. Its a new long block with about 1500 miles on the rebuild. Most everything is new that can be.
According to my manual, it says with the key in the ON position, the voltage on the coil should only be 1 volt less than what is at the battery. Mine is half. If i disconnect the negative side of the coil, the voltage jumps up to where it should be. Also, if i leave the negative on the coil and then disconnect the ECU, the voltage again goes up to where it should be. I have looked and looked and dont know what I am missing. The truck will start with the voltage at 6.7v at the coil. Its alot harder to start after its hot though.
I have put on a new ECU, starter relay, ballast resistor and checked the resistance on the coil.
Does anyone have any idea why the voltage is so low at the coil?
You are supposed to have battery voltage -1 volt at the coil in the "start" mode. With the truck in the "run" mode(key only on) you will have about half that voltage because the voltage during "run" goes through the ballast resistor and is reduced.
