Fuel Pump Issue

[Shoulder]

I have a 1989 Fleetwood Pace Arrow. It is a Ford chassis with a gas 4bbl Holley carb. The fuel pump (electric right in front of the gas tank) was replaced by the last owner because when I went to buy it the pump wouldn't work. Well I don't think it was the pump that was bad. I wasn't involved with the repair (you can tell the pump is new).
The carb. keeps running out of fuel. so I checked the fuel pump inertia switch. I tried to reset it. It was not tripped. (camper hasn't been driven in 2 years). I checked the voltage at the relay connector (unplugged) with the key in the run position .5-.8 volts. Same voltage with the key in the off position. Turn the main power switch above the door off. The voltage reading goes to zero in all positions. When I turn the switch to start (while cranking) the voltage bounces between .6-5.12 volts. Plugged the connector back into the relay and probed the wires at the pump. The results are the same. This tells me the relay is ok. I jumped the pump with a 12v battery and the pump filled the carb with fuel and started.
Something is wrong in the wires but I can't find a fuse or a fuel pump relay so I have no idea where the short or break might be.
I checked both fuse panels under the dash and under the hood. I know in cars there is a fuel pump relay somewere (under the drivers seat in a mustang). I think the relay might be bad but I have no idea were to look. I don't want to run a bypass wire I really want to fix it the right way.Can someone PLEASE help me with this. I have been pulling my hair out trying to fix this.

Sorry its so long but I wanted to give as much info as I could.

Thank-you
Bob

 

[C Nash]

Re: Fuel Pump Issue

Bob, not familar with your system w/o seeing a wiring diagram. Most have a delay relay that supplies voltage for several secomds seconds when the switch is turned on then the voltage is switched to another relay or most work through the oil pressure switch.

 

[TexasClodhopper]

Re: Fuel Pump Issue

Bob, the the voltage readings you are giving could indicate burned contacts on a relay.

It could also indicate burned contacts in a connector.

These symptoms would also be in character for a high current device like a fuel pump.

You have to find that relay or connector.

 

[Shoulder]

Re: Fuel Pump Issue

Thank-you for the replies. I am thinking like both of you. The fuel pump should “spool up” for 10-15 seconds to pressurize the line and then run off of the oil pressure sensor. I do not have a wiring diagram and have not been able to find anything that shows where this circuit runs through.
I do think there is a bad relay or at least a corroded one. I have no idea where it could be. I have checked all the places I would think they would hide it but with no luck. This thing is killing me.
MORE HELP PLEASE?
Bob

 

[Shoulder]

RE: Fuel Pump Issue

I put a jumper wire across the oil pressure switch sender that I think is for the fuel pump. I also put a volt meter across it no voltage present with the key in any position. Now what??????????
Bob

 

[C Nash]

Re: Fuel Pump Issue

Bob, have you checked all your fuse? A call to Fleetwood might get you the location of the relays, fuse and maybe a diagram but don't hold your breath.

 

[Shoulder]

Re: Fuel Pump Issue

No I didn't
I did try to look at their web site to see if any diagrams where on there but I didn't see any.

Bob