29.06.2023, 19:56
Thomas, du hast recht.
Ich habe nie ein Diagramm besessen - ich habe mich einfach daran erinnert, was hier im Forum schon mal ein Kollege geschrieben hat
und das schien mir schlüssig.
Ich habe in meinem beträchtlichen Fundus von gespeicherten Links zu Beiträgen einen Link zu einem Beitrag aus dem US-Forum
Corvetteactioncenter.com gefunden, der deine Darstellung bestätigt, leider kann man nicht mehr auf das dortige Diagramm zugreifen.
So here's the order that things happen in the circuit:
!) Ignition switch is turned on. The ECM sends a signal to activate the fuel pump on Relay connection "C", with a return ground on "B". The relay closes output contacts "A and "E" which sends +12V to the fuel pump fuse, through it and to the Fuel Pump, and starts the fuel pump.
The fuel pump runs until the pressure comes up in the fuel system then shuts off. (Note:The fuel Pump shuts off by itself, not because the relay did. It has a pressure sensor in it and the relay is still on).
2) The "C" input will stay energized (Closing "A" and "E" contacts) while the engine is cranking until it starts.
3) Once the engine starts, the Oil Pressure Switch closes a set of contacts that short the "A" and "E" wires together, essentially bypassing the Fuel Pump Relay as long as the engine is running unless you experience a loss of oil pressure, or the ignition is turned off.
So the Fuel Pump Relay only works during the starting and cranking phase of the cycle. Once the engine has started, it turns off and the fuel pump is kept on by the Oil Pressure Switch (that black cylinder thing with the 3-wire connector on the engine block ) next to the distributor.
Hope this helps.
Beste Grüße
Gerd
Ich habe nie ein Diagramm besessen - ich habe mich einfach daran erinnert, was hier im Forum schon mal ein Kollege geschrieben hat
und das schien mir schlüssig.
Ich habe in meinem beträchtlichen Fundus von gespeicherten Links zu Beiträgen einen Link zu einem Beitrag aus dem US-Forum
Corvetteactioncenter.com gefunden, der deine Darstellung bestätigt, leider kann man nicht mehr auf das dortige Diagramm zugreifen.
So here's the order that things happen in the circuit:
!) Ignition switch is turned on. The ECM sends a signal to activate the fuel pump on Relay connection "C", with a return ground on "B". The relay closes output contacts "A and "E" which sends +12V to the fuel pump fuse, through it and to the Fuel Pump, and starts the fuel pump.
The fuel pump runs until the pressure comes up in the fuel system then shuts off. (Note:The fuel Pump shuts off by itself, not because the relay did. It has a pressure sensor in it and the relay is still on).
2) The "C" input will stay energized (Closing "A" and "E" contacts) while the engine is cranking until it starts.
3) Once the engine starts, the Oil Pressure Switch closes a set of contacts that short the "A" and "E" wires together, essentially bypassing the Fuel Pump Relay as long as the engine is running unless you experience a loss of oil pressure, or the ignition is turned off.
So the Fuel Pump Relay only works during the starting and cranking phase of the cycle. Once the engine has started, it turns off and the fuel pump is kept on by the Oil Pressure Switch (that black cylinder thing with the 3-wire connector on the engine block ) next to the distributor.
Hope this helps.
Beste Grüße
Gerd
Gerd82