warover
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I learned today that the Fuel Pump Relay differs from other 5 pin Relays in that it has two 87 ins as oosed to an 87 and an 87a. Does anyone know why it has this configuration? Are they interchangeable?
Fuel Pump Relay-two 87's
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tomcat59alan
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Check the wiring diagram on the relay. Are 87 and 87a just bridged so both become live when the relay is activated, so power two circuit? If the relay diagrams are not the same then they are not interchangeable. Just guessing now, to cold to go in my garage to have a rummage in my relay box, sorry. May post later
tomcat59alan
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What year, engine? The MFI had a safety feature, controlled by the ECM, that cut out the fuel relay if the ignition was left in position 2 for too long. Could be something to do with that.
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Some Engine ECU/Fuel Pump relays had a diode fitted....
classic kev
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To add to what has already been said, a 5 pin relay can be used as a changeover relay or to provide power to two circuits. Don't know what motor we are talking about here or injection system but I do know that on hotwire injection system the main efi relay and fuel pump relay are interchangeable, they both have diodes in them. If you look at the relay it should have a diagram on it showing what it does. The fuel pump and main EFI relays should only be changed for a similar relay rated at 30A with a diode.
The diode is there to protect the components/circuit from back emf. (IIRC)
Now about the terminals, two 87's would be for providing power to 2 separate circuits at the same time when the relay is closed (depends if relay is normally open or normally closed) - that is certainly the case for the main efi relay which sends power to injectors, ECU and air flow meter ( I know that's 3 but there is a splice in there O.K!) Fuel pump relay appears to provide power for fuel pump and lamda sensors. So the 5 pin relays are not changeover in this application ('91 RRC).
Think I've got that the right way round, HTH
The diode is there to protect the components/circuit from back emf. (IIRC)
Now about the terminals, two 87's would be for providing power to 2 separate circuits at the same time when the relay is closed (depends if relay is normally open or normally closed) - that is certainly the case for the main efi relay which sends power to injectors, ECU and air flow meter ( I know that's 3 but there is a splice in there O.K!) Fuel pump relay appears to provide power for fuel pump and lamda sensors. So the 5 pin relays are not changeover in this application ('91 RRC).
Think I've got that the right way round, HTH
tomcat59alan
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warover
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First of all, the subject vehicle is a 1991 Range Rover Classic equied with the 3.9l engine. The Fuel Pump Relay is: Bosch 0 332 014 112. Here is the layout:
tomcat59alan
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First of all, the subject vehicle is a 1991 Range Rover Classic equied with the 3.9l engine. The Fuel Pump Relay is: Bosch 0 332 014 112. Here is the layout:
I cannot open it
warover
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In the ost that you are unable to open, I provided the following:
1. The vehicle is a 1991 Range Rover Classic with the 3.9L engine
2. The Fuel Pump Relay is the Bosch 0332014112
3. I included a diagram of the 5 pin configuration which is the familiar 5 pin layout. In addition, there is the cchematic that shows the two 87 pins that are activated and powered simultaniously. This is different than the other 5 pins that on the surface apear to be the same as this one. This came to light when I was attempting to bench test them. The resistance is different as well. However, I do not know if my reading are what they should be or if the relays are defective. I also think that the main relay and the fuel relay are different. Based on my review of RAVE, this Fuel Pump Relay is not unique t6o the 1991.
1. The vehicle is a 1991 Range Rover Classic with the 3.9L engine
2. The Fuel Pump Relay is the Bosch 0332014112
3. I included a diagram of the 5 pin configuration which is the familiar 5 pin layout. In addition, there is the cchematic that shows the two 87 pins that are activated and powered simultaniously. This is different than the other 5 pins that on the surface apear to be the same as this one. This came to light when I was attempting to bench test them. The resistance is different as well. However, I do not know if my reading are what they should be or if the relays are defective. I also think that the main relay and the fuel relay are different. Based on my review of RAVE, this Fuel Pump Relay is not unique t6o the 1991.
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