2003 fuel pump relay problems
#2
An excessive current flowing though their contacts (but below the fuse ratings) can also cause local overheating - in this case you should be looking for problems with the loads connected downstream from these relays. Take one relay out at a time and connect a multimeter - configured as a ampmeter - to the load pins of the relay socket. Be careful not to connect the leads to the relay coil pins in the relay socket, this will toast your meter in no time, and may harm your car as well!! If you see a higher than normal current flowing through, you just found your culprit. What is normal depends on the car, you should look in the service manual or compare with a known good, similar car, to get the numbers.
You can also see this problem if the relay socket or its wiring are loose, causing poor electrical contacts that heat up when passing high currents. Clean the contacts in the relay socket with a small strip of 400 grit sandpaper folded in two so it is abrasive on both sides.
Good luck, and let us know how it goes!
Last edited by cougar_fan; 12-01-2011 at 10:10 PM.
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jozepy24
Ford F-250 & Ford F-350
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fordexpedition2006
Ford Expedition
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03, 2003, aftermarket, expedition, expiedition, f350, ford, fuel, pcm, problem, problems, pump, pumps, relay, works