Wire identification 81 c30 dually

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RottenSquare

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Ontario
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Marek
Truck Year
1981
Truck Model
C30
Engine Size
454
Trying to identify the blue and green wires that come out of the cab. Truck is a factory 350 4 speed. Now has a 454 turbo 400.
Some posts I have found state those are for an electric torque converter lockup on a turbo 350... But truck was not a factory auto. . .

Then trying to figure out what the resty silver module is for behind the distributor. It was sitting in the valley of the engine, left of the carb.
It has a tan like wire coming from the firewall bulk head (engine side harness) from there it goes to a taped up two wire plug. And had a second yellow wire coming back into the cab (was spliced), it also has a ground wire attached to the head on the right side.
Not sure what it was for, any insight or ideas would be great.
 

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RottenSquare

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Marek
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1981
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C30
Engine Size
454
Any help or guidance would be appreciated. Been searching high and low, and am unable to get a solid answer unfortunately.
 

RottenSquare

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1981
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C30
Engine Size
454
I may have found the answer to the one item... the module on the firewall. Looks like it was a relay for a SMOG pump. Or something along the lines. looks like its not needed then.... As for the other wires, could they be for reverse lights?
 

Craig 85

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K30 SRW
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454/TH-400/NP205
The relay on the firewall could be for the pod on the driver's side front of the carb. Mine is mounted on the valve cover. On my '85 it opens the carb a hair to prevent back fires between certain RPM's.

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RottenSquare

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Marek
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1981
Truck Model
C30
Engine Size
454
The relay on the firewall could be for the pod on the driver's side front of the carb. Mine is mounted on the valve cover. On my '85 it opens the carb a hair to prevent back fires between certain RPM's.

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Dang!!! Thank you so much. That is probably what it is.... It was that Solenoid on my carb was bypassed to a switch on the dash. Was used as a high idle switch. Very cool! Thank you for this!
 

Craig 85

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Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
Dang!!! Thank you so much. That is probably what it is.... It was that Solenoid on my carb was bypassed to a switch on the dash. Was used as a high idle switch. Very cool! Thank you for this!
My ‘85 is setup this way. The pod on the carb is vacuum operated. There is an electric solenoid mounted on my thermostat housing that connects to the pod. I believe the relay on the valve cover ties into my electric solenoid based on RPM, it then opens the vacuum to allow the pod on the carb open between 1600-1900 RPM when decelerating.

On the ‘79 half ton with a SBC it had an electric solenoid to bump the idle when the A/C was on.
 

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