Expert: Sean Halliday - 7/9/2006

Question
Sean,
    I have a 1985 Mazda RX-7 GSL-SE (fuel injected 13b rotary engine). I just replaced the fuel pump, filter, and refurbished the gas tank. It won't start and I believe that no power is getting to the fuel pump (yes it is connected electrically). I don't know where to locate the fuel pump relay or any other component within the electrical path to the pump. I don't think it passes through the interior fuse box, but regardless all fuses in that box appear to be fine. I noticed there is no electrical hum sound from the rear like I used to hear when the car ran properly. I'm getting nothing at all from the pump. Any suggestions?
Thanks,
Shawn
Additional info: There have been some other strange electrical issues happening. In recent months my rear wiper/washer and defogger stopped working.  My rear hatch light quit too, but the bulb is fine.

Answer
The rear wipers wont be on the same relay.The fuel pump relay is seperate from all the others.Unfortunately the relays can be anywhere so you will need to get a manual as i dont have a book on this car.Sounds like you have 2 or maybe more faulty relays.Did you test the fuel pressure at the rail?Should be 45 PSI(approx) ,if you are not gettin any then its definately the pump.Make sure the connections are tight on the pump.You can get a book on this car on ebay or look on the web for car manuals,I have found most times the fuel pump relay is under the dash on mazdas.Black or blue in color.As for the rear problems look at the wiring going to the wipers and light,maybe worn or cut.I have found that this relay is sometimes beside the accelerator pedal connected to a bracket in this area ,or just above it.Mazda use a safety system which is hooked to your throttle body/air flow.So if you roll your car you dont have a huge fuel leak/fireball.This kills the fuel flow and this relay does give problems like you describe.So thats where it should be under the footwell drivers side.This relay will only work when the key is in the ON position.From memory i think it might be metal in color like silver/bronze.PS,,,,,,the relay will have 4 wires to it,the connector has a 6 wire block,,,,,hope this might help some,