Lews83GS

Hi, I've been restoring a 1983 for almost a year now and am working on the interior. After a carpet install and a combo switch (turn signals/lights) replacement my fuel pump quit, I don't think I disconnected any wiring accidentally and I did check all visible connectors and from what I can tell the power supply doesn't run through the combo switch. I checked for power at the fuel pump connector under the storage box it had no power, Then I checked the fuse its good but the fuse is not getting power at the box. From what I can tell the S2 doesn't have a fuel pump relay like the S3 does. After looking at the wiring diagram I'm thinking ignition switch. Has anyone had this problem or have any advice? Thank You.

mazdaverx713b

iTrader: (91)

Are you getting 12V to the pump connector when the engine is cranking over? Have you attempted to apply 12V direct to the pump connector to determine if it can be powered with direct power?

Lews83GS

I've checked the pump connector, no power. I'm thinking I need to try the direct 12v power as you suggest. I've read several post where they just bypassed the original wiring, just trying to decide what it should be connected to.

KansasCityREPU

iTrader: (9)

Use the schematic to trace the 12v source back till you get it. You might need to be cranking to get the 12v to the pump.

Lews83GS

Thank you for the idea, I used the schematic and figured out the ignition switch was good and had power to the fuse box, but could not find power coming back from the pump. I went ahead and ran a new switched 12v source with 10 amp fuse to the pump and have it working. I'm not sure what happened to the original power supply, that will have to wait until another day.

mazdaverx713b

iTrader: (91)

You may find that you have a small break in one of the wires in the harness that feeds power to the fuel pump. It's a short routing honestly. You'll have to remove the driver's seat and pull the carpet up to expose the harness. Will lead you right to the pump under the storage bin frame from the fuse panel. Should be able to see if any wiring was chewed by a rodent or if something was flexing where it shouldn't and ruined through the harness and caused an open in the circuit.

DreamInRotary

iTrader: (49)

Glad to hear you got it sorted! As mazdaverx713b said, could be a small wiring issue that crept up over time (like chafing or wear) that will be difficult to track down. What matters is that for now your car runs!

KansasCityREPU

iTrader: (9)

This is a very good point. Running a new 12v source is a good way to verify that everything after that connection is good. The gotcha is that if the original wire is compromised, it could over time create a short and blow fuses. Hunting it down after a new 12v source has been ran makes it harder.

LongDuck

We've all had to deal with issues from prior owners that half-fixed things that make it difficult to know what's going on. One of the big benefits of the FSM and the knowledge on his board is that if it's in factory configuration, someone can tell you how to fix it from a thousand miles away.

Start plugging crap together, bypassing factory wiring, and you're on your own from that point forward. I learned this while troubleshooting my SE short that turned out to be the Bypass Air Control Valve harness shorting against the solenoid body, when I thought it was the Fuel Pump Relay - not even close in proximity.

Put some additional effort to find the root cause and you'll be thanking yourself later, and will retain confidence in the vehicle. Every workaround kills confidence when stuff breaks or stops working...