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Old 05-12-2025, 08:11 AM   #26
Detour
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Join Date: May 2024
Location: Appleton, WI
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Re: Lose spark after cranking

Wiring is fixed... somehow... I pulled everything apart again, checked all the wiring, replacing only one wire for the windshield wipers and everything works now. Ignition was the resistor wire and jumper wire from the starter. Eliminated the jumper and replaced the resistor wire with a regular wire and the engine runs with no electrical issues but something is seriously wrong with the new carb now. This truck is haunted....
Thanks everyone for all the help
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Old 05-12-2025, 12:49 PM   #27
RustyPile
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Location: Elkhart, Texas
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Re: Lose spark after cranking

Quote:
Originally Posted by Detour View Post
Wiring is fixed... somehow... I pulled everything apart again, checked all the wiring, replacing only one wire for the windshield wipers and everything works now. Ignition was the resistor wire and jumper wire from the starter. Eliminated the jumper and replaced the resistor wire with a regular wire and the engine runs with no electrical issues but something is seriously wrong with the new carb now. This truck is haunted....
Thanks everyone for all the help
The "Something is seriously wrong", is probably not the carburetor.. The ignition components are designed to have a resistor in line between the coil "+" terminal and the ignition switch. The purpose of this resistor is to reduce the voltage applied to the coil. A "regular wire" will not do this. That yellow wire from the starter to the coil is also there for a purpose. It bypasses the resistor wire during the time the starter is engaged. Your work is not finished just yet.
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Old 05-12-2025, 04:11 PM   #28
PbFut
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Re: Lose spark after cranking

The resistor wire is there to protect the points. Pretty sure the oem coil can, and certainly all aftermarket coils are designed for a full 12v. If you are using a pointless distributor, and for sure HEI type, it is required that the resistor wire be replaced with a fully conductive wire. Doing so renders the jump wire to solinode moot. Leaving a resistor wire in place while using a HEI distributor will prematurely burn out the amplifier board on a HEI set up.
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Old 05-12-2025, 09:58 PM   #29
PbFut
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Re: Lose spark after cranking

I got a little schooling on the resistor wire today. It is there to lower long term voltage to the OEM coil to help protect from overheating. The condenser protects the points. I still stand by my statement that the resistor wire is not needed unless you are using a 50 year old OEM coil. If you are using a modern coil, HEI dizzy, and probably most CDI boxes you should eliminate the resistor wire.
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