Fuel Pump Wiring Issue
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Fuel Pump Wiring Issue
How many sources of electric power are available to the fuel pump?
I had thought power could only come from the key switch while in start position or through the oil pressure with engine running and pressure.
I put a rebuilt 460 engine back in a 1983 460 Econoline motor home with twin fuel tanks and reconnected wiring. I hooked up battery and fuel pump began pumping. Key is not even in the switch.
I did not think there should be any current available to pump unless key in start position or oil pressure up with engine running.
Help appreciated.
Ard ardb@aol.com
I had thought power could only come from the key switch while in start position or through the oil pressure with engine running and pressure.
I put a rebuilt 460 engine back in a 1983 460 Econoline motor home with twin fuel tanks and reconnected wiring. I hooked up battery and fuel pump began pumping. Key is not even in the switch.
I did not think there should be any current available to pump unless key in start position or oil pressure up with engine running.
Help appreciated.
Ard ardb@aol.com
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Thanks for the reply. I was just about to e-mail you. I have been working with this same diagram that I got from you a couple of years ago.
No wires were removed from the starter relay during engine removal. Removing a relay which I believe to be the tank selector relay stops the pump which would be normal. That relay was replaced last spring when only the rear fuel pump would work.
After studying diagram last night, I will check out the fuel pump cutoff relay behind the inertia switch which appears to be always hot from the battery. If it is stuck in closed position that could cause the problem. (I think)
The only other source I can think of would be if the starter relay was shorted which doesn't seem reasonable since the starter motor is not being activated when battery cable is hooked up.
I will post later today after checking the fuel pump cutoff relay
Thanks again, Ard
No wires were removed from the starter relay during engine removal. Removing a relay which I believe to be the tank selector relay stops the pump which would be normal. That relay was replaced last spring when only the rear fuel pump would work.
After studying diagram last night, I will check out the fuel pump cutoff relay behind the inertia switch which appears to be always hot from the battery. If it is stuck in closed position that could cause the problem. (I think)
The only other source I can think of would be if the starter relay was shorted which doesn't seem reasonable since the starter motor is not being activated when battery cable is hooked up.
I will post later today after checking the fuel pump cutoff relay
Thanks again, Ard
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Problem fixed. Fuel pump cutoff relay was full of water. Vehicle w/o engine was sitting outside w/hood off. Relays were not fastened to fender liner panel but hanging by wires behind battery.
Replaced relay and system works fine.
Thanks again Bill for your reply
Replaced relay and system works fine.
Thanks again Bill for your reply
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