Please help!! 1971 340 duster having major ignition wiring headaches.
DIAGRAMS BE CAREFUL
Aftermarket, simplified wiring diagrams can lead you astray, there are two general problems
1: Some diagrams show the box connector looking INTO the FRONT of the WIRE end harness connector. Some diagrams are drawn as looking at the FRONT of the box itself This produces a MIRROR image. This diagram is looking down at the front of the BOX
2...Second and this is a MISTAKE is some label the BYPASS circuit as if it goes to "START." THIS IS NOT CORRECT.
In the diagram below, the "S" START wire at top right DOES NOT come from the (normally) yellow "start" wire from the key, and which fires the "start" relay. This instead comes from IGN2 on the key which is a SEPARATE contact to prevent backfeed
HOW THIS works. With the key in run AND ONLY IN RUN and in NO other position, the blue "run" wire feeds power into the engine bay. This goes through the ballast to the coil, and branches off to the ECU box
Most any box you will find nowadays is a FOUR wire box, and if plugged into EITHER a factory 2 terminal ballast harness, or a 4 terminal ballast harness, WILL work. A true 5 pin box will NOT work with a 2 pin ballast. YOU CAN NOT identify a 4 pin box by looking, as some have 5 physical pins
WHEN STARTING, and the key is held to "start", the IGN2 terminal of the key becomes live and sends power to the wire labled START. The RUN IGN1 line (bottom right) GOES DEAD at the key. The BYPASS/ IGN2 circuit (labled start) IS THE ONLY power during cranking.
This power feeds through the terminal on the ballast, direct to the coil, and SHOULD provide near full battery voltage to the coil for start. The NEG side of the coil goes to the box and to ground---THE BOX MUST be grounded.
HOW DOES the box get power for starting. Power at the top terminal of the ballast flows through the ballast and over to the box, so the box actually receives REDUCED voltage during cranking. (Why this was done the way is beyond me)
DIAGRAMS BE CAREFUL
Aftermarket, simplified wiring diagrams can lead you astray, there are two general problems
1: Some diagrams show the box connector looking INTO the FRONT of the WIRE end harness connector. Some diagrams are drawn as looking at the FRONT of the box itself This produces a MIRROR image. This diagram is looking down at the front of the BOX
2...Second and this is a MISTAKE is some label the BYPASS circuit as if it goes to "START." THIS IS NOT CORRECT.
In the diagram below, the "S" START wire at top right DOES NOT come from the (normally) yellow "start" wire from the key, and which fires the "start" relay. This instead comes from IGN2 on the key which is a SEPARATE contact to prevent backfeed
HOW THIS works. With the key in run AND ONLY IN RUN and in NO other position, the blue "run" wire feeds power into the engine bay. This goes through the ballast to the coil, and branches off to the ECU box
Most any box you will find nowadays is a FOUR wire box, and if plugged into EITHER a factory 2 terminal ballast harness, or a 4 terminal ballast harness, WILL work. A true 5 pin box will NOT work with a 2 pin ballast. YOU CAN NOT identify a 4 pin box by looking, as some have 5 physical pins
WHEN STARTING, and the key is held to "start", the IGN2 terminal of the key becomes live and sends power to the wire labled START. The RUN IGN1 line (bottom right) GOES DEAD at the key. The BYPASS/ IGN2 circuit (labled start) IS THE ONLY power during cranking.
This power feeds through the terminal on the ballast, direct to the coil, and SHOULD provide near full battery voltage to the coil for start. The NEG side of the coil goes to the box and to ground---THE BOX MUST be grounded.
HOW DOES the box get power for starting. Power at the top terminal of the ballast flows through the ballast and over to the box, so the box actually receives REDUCED voltage during cranking. (Why this was done the way is beyond me)
