GenWunner

Hey all. I'd been having intermittent fuel delivery issues, which has caused me to check everything I could possibly think of. I'm pretty sure the fuel pump is no longer(suddenly) receiving power, as I've verified it works with a bench test, but it doesn't seem to work when connected to the car. I would now like to conduct a bench test of the fuel pump relay, and I'm having some trouble understanding where I should connect the power input. I've pulled out the relay, and it doesn't have any kind of diagram on it, so I'm checking the wire diagrams from the FSM. Unfortunately, it's a little beyond my expertise, so I was hoping someone could help me out.

(I'm not sure why this picture came out so large, I shrank it on my post)

The only differentiation between the prongs seems to be the numbers 1, 2, 3, and 5
Which corresponds to the below portion of the wiring diagram, indicating the wire colors


Now, looking at the diagram below (and making some educated guesses), I traced the line from the battery to the relay, and it looks like the pins that should be connected to the multimeter are 1 and 2(with the positive connector on 2, and the negative on 1), and the power supply should be connected to pins 3 and 5(with the positive on 5, and the negative on 3). I just want to make sure that I have this right so that I don't accidentally fry a potentially functional relay


I should note that I've searched the RX7club forums and youtube without anything helpful for this particular relay.

KansasCityREPU

iTrader: (9)

Jump the pins BW and LW on the fuel pump relay connector B-06.

peejay

The fuel pump relay is an NC relay. Meaning, the engine control computer has to actively power the relay coil to shut the fuel pump off.

Why are you bench testing the relay? Everything you need to know is in the car, not the relay.

GenWunner

Ahh, it seems I had a fundamental misunderstanding of how the relay works. I guess I'll try to bypass the relay
This answers what would have been my next question. Thank you so very much

GenWunner

Update: Put together a bridge wire with a short 12ga auto wire with 1/4" male quick disconnects on both ends, and it didn't work(Thingy I made). Yes, I stripped the rubber coating off both ends before putting on the contact points. I'm assuming I did something incorrectly, because I don't know what else would be preventing the fuel pump from running. I know it works from a bench test, and I've verified that the positive and negative wires on the fuel pump are connected correctly.
I thought it would be impossible to find a proper replacement, even an expensive one. Fortunately, I found a cheap replacement on ebay and decided to just buy it, since it's only ~$15 with free shipping.

peejay

An aside, since I do do this for a living and forget that sometimes what I see as obvious isn't always obvious

In a diagram with a relay, the relay internals are always shown in the unpowered state. This is very helpful when seeing a diagram with a multi pin relay that has both NC and NO outputs (or inputs, depending on how it is wired) So in that diagram, when you look at the relay, you can see that the contacts are closed. This means that when you power the coil, it opens the contacts.

The connector for the fuel pump is under the driver's side storage bin. If you have the typical wheel well rust and water leak, the connector can get corroded. Both power and ground go through the connector.

KansasCityREPU

iTrader: (9)

Double check that you have 12V on the BW (Black White) wire in that connector. The other thing you can do is put 12V and ground directly to the connector in the bin area.