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I've been scrutinizing the electrical schematics for the 94 model 940, and noticed a few things that weren't clear to me before.
I said yesterday that some of the 940's there are two seperate fuel relays....one under the dash on the relay terminal and one under the hood near the coolant resevoir.
This is true. My 94 model with Bosch LH 2.4 injection has two.
One (the Fuel Pump Relay) is on the relay terminal located behind the ash tray.
This small blue cube relay powers both the intank and Main fuel pumps.
The 12V power supply to this relay comes directly from fuse #1 (25 amp) and remains constantly energized.
This relay is operated (on-off) by a (negative) ground signal from the Jetronic Module (terminal 9).
The 12V secondary output from this relay powers the Main fuel pump directly (thru the 25 amp fuse) and also powers the in-tank fuel pump and fuel level sensor, and the oxygen sensor thru fuse #11 (15 amp).
The second relay (Radio Interference suppression) is located under the hood near the coolant resevoir.
This relay is rectangular and black.
The 12V power supply to this relay comes directly from the battery and remains constantly energized.
This relay is controlled (on-off) by a (negative) ground signal from the Jetronic Module (terminal 21).
The output supplies 12V power to the fuel injectors, the Mass airflow meter and the Idle air control valve.
The fuel injectors and idle control valve are operated by a (negative) Ground signal from the Jetronic Module.
Fuel injectors...terminal 18.
Idle Control Valve...terminal 33.
The Air Mass meter is also operated by the Jetronic Module.
I also own a 93 Model 940 with Regina Fuel injection and it only has 1 fuel relay located behind the ashtray. This is the conventional relay that I am used to seeing on the Volvo 240's with LH 2.2 and LH 2.4 injection that I've owned.
If any of this is incorrect I'm sure that I'll hear about it
The electrical schematics that I reference are from "Mitchell Repair Information Company".
Hope this helps
steve
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