Need some guidance on getting my 74 1.8 fired up again. The car was running fine on a cruise. It left me stranded and now the fuel pump (FP) will not turn on. This is what I have attempted based on searches:

-checked main power and FP relay by swapping into headlights, both operate fine
-FP fuse is good
-ohm'd and powered dual relay, seems to operate fine
-dual relay ground is good
-manually moved AFM flap, dual relay clicks but FP does not come on
-jumped pin 30 to 87 on FP relay, FP turns on and car cranks but will not start
-jumped pin 13 on 14 pin connector, FP turns on
-checked FP ground
-ohm'd AFM as outlined in Haynes manual, resistance is within spec

It should be noted that prior to when the car was running, I would wiggle the AFM connector and it would trigger the FP to turn on and off. Now if I wiggle it, I only hear the dual relay clicking but no FP.

The yellow wire on pin 86A of the dual relay is not connected and explains why the FP was always on with key in the ON position before the car stopped running. But i'd like like to fix that wiring once I can get it running again.

Any help is appreciated

First.. forget about all the relays on the relay board. They do nothing on an L-Jet car. You can take them out and the car will still run.

The yellow wire on the dual relay goes to the relay board. It hooks to the four pin connector located on the left rear. Hook it to the right rear pin. This wire provides power to the fuel pump when the engine is cranking.

Feed +12V to the yellow wire at pin 86a on the double relay and the fuel pump should run.

Feed +12V to pin 86C. The fuel pump should run. If it does, then replace the double relay. If it doesn't, then feed 12v to pin 12 on the connector between the engine harness and the relay board. If the pump runs, then the engine harness has a broken black/red wire between the double relay and pin 12 of the relay board. If it doesn't, replace the relay board. The relay boards are notorious about getting loose connections on the rivets. You can run an ohm check with a DVOM to see. The 12 pin connector on the relay board should connect to both pin 13 on the 14 pin connector, and pin 87 on the fuel pump relay socket.

Let me know what you find.



Hope that helps.

Thanks for the response ClayPerrine. I tried your suggestions and here are the results:

-I connected the yellow wire to pin 86A on the dual relay and to the specified location on the relay board. I fed it +12V and the pump did not run. I only heard the relay clicking. What are the next steps I should take since it should've ran?

- I fed +12V to pin 86C on the dual relay and the fuel pump did not run

- I fed +12V to pin 12 on the relay board and the fuel pump turned on

- I also ran a continuity check between pin 12 on the relay board, pin 87 on the fuel pump relay socket and pin 13 from the 14 pin connector. It all checked out fine.

Does this mean that I can rule out the relay board and narrow it down to the engine harness having a broken black/red wire between the double relay and pin 12 of the relay board?

Thanks again for the help

Do an ohm check between pin 88d on the double relay and pin 12 on the relay board 12 pin connector. If this checks out, replace the double relay. If it doesn't, then track down where the wire is broken.


Clay

Did a continuity check between pin 88d of the dual relay and pin 12 on the board, it checked out fine. I ordered a new dual relay, hopefully it arrives before Monday (I leave back to college on Monday)

Will keep you posted

Marc

If the dual relay is a metal can, then you will have to alter the plugs to get the new plastic relay to plug in.

Mine has the plastic relay installed already.

I finally received the replacement dual relay from RockAuto. Unfortunately, I'm away from the car since summer school began this week. I'll be sure to post updates as soon as I'm home again