n mud pumps

Fuel pump relay location

npx84

I have a '93 Rockwood on an F53 Chassis that I am going to be selling in the spring, but one problem that I have had the last few years going out on the weekends with it was that after anywhere from 10-40 miles, the fuel pressure drops off to around 10psi and it runs like garbage until you shut the key off and restart it. I usually do it while coasting down the road. Then it is ok again for a while. So anyway, I want that fixed before I sell it. I have replaced the fuel pump twice for other reasons. The fuel pressure regulator (distributor) has also been replaced on the 460. Filter has been done as well. I figure the only thing that makes sense is the Fuel pump relay (seeing that it "resets" itself when cycling the ignition). But I can't find it. If anyone knows where it is, please enlighten me. I have looked under dash with other fuses as well as on the "fire wall" no boxes with relays can be found.

Unplanned Traveller

Odd that it just drops fuel pressure, but keeps running. It really sounds like a restriction somewhere. Usually when a relay cuts out, it goes to zero volts. I'm guessing your pump is in the tank, so if there was something floating around in there could it be getting drawn up around the intake and restricting it there? I have seen that in truck fuel tanks where a shop rag gets into a tank somehow and causes a problem much the same as you have.

Outbound-iRV2

I have seen tank type fuel pumps with fabric type screens suck the screens into pump and reduce flow, might want to take a look.

olcarguy

Definitely sounds like something being sucked into the inlet of the pump, not blocking enough to stall the engine, when you recycle the pump it drops away till it gets sucked back up again...just a thought.

npx84

Thanks for the suggestions. I don't think it is anything in the tank/pump. I put a new one in myself. I replaced the original one because the guage didn't work and it must have drained back in the tank as it took a long time to start. The new one failed in about 200 miles. Changed it again and this one has been working good for 3 seasons. Made sure nothing was in the tank. I cleaned it out really well. When it happenens, it seems electrical just by the way it acts. I just can't seem to find the relay anywhere.

David L1

Put a volt meter on the pump to reject or condemn the electrical wiring from the problem. You should have near battery voltage at the pump at all times. You can put some extension wires to view the voltmeter in cockpit. Make sure all are insulated well to minimize any electrical short problem.

quincy-ORO

This is only speculation but I think that relay and others are supplied by Ford and located by the MH Mfg. so my 99' Newmar has them behind the dash board on the drivers side. I had a 95' Pace Arrow that had them under the dog house way forward past the opening so they could barely be seen let alone reached. That was a Chevy but it might help with your search. Hope this helps and good luck. Let us know please.