Residual Fuel Pump Relay Voltage Reply #15 – August 10, 2007, 11:26:57 PM also,, taking a look at pins 57 and 37, these leads could be providing feedback power to the coil after the fuel pump relay timer circuit has removed the ground provided on pin22 under the KOEO condition.either way, pin 22 should open and close the circuit or "control" the coil to the fuel pump relay.Since the meter requires a ground to get a voltage reading, and reading directly off the socket or with the fp relay installed should and will give two different effects.ill stick with the results while the relay is plugged in cause thats duplicating the instance we are dealing with.so...with the fp relay installed in a koeo condition,softouch got this reading and it says the ground is controlled like id expect."Across the relay coil:K-OFF 0.00KOEO 11.15--2 sec--0.01K-OFF 0.01---5 sec--0.00"what is confussing to me is its not actually correct to say "EEC side of coil" because both sides of the fp relay coil end up at the eec either at pins 57&37 or pin 22.to rewind a little, softouch has been able to obtain a different reading than what you have there jeremyb. His reading across the fp relay coil goes to zero in a koeo situation after two seconds,,, yours stays around and trickels down to a full 7vdc. If what i suggested earlier is possible and you are getting feedback from eec pins 57 and 37, the only option for the missing link is an unwanted ground on the tan light green.If your getting an unwanted ground , feedback is possible cause your key is still on although the engine is not running,,,,so the EEC relay is still putting power down to the inertia switch side of the fuel pump relay. Continuity check the tan light green from the eec test conn back to the fuel pump socket and from the eec to the fuel pump socket. Lastly check the tan light green from the eec to the eec test connector.if you have issues such has high resistance,, do a wiggle test on the harness in various areas.if you can make this 7vdc go away, your getting closer to the defect , dont forget to tap on the fuel pump relay to see if you can make the 7v go away also.if you have grounded out the wrong wire by accident on the fuel pump socket in order to get the pump running, its likely the pin 22 side of the eec is defective again. Thats whats up with my old eec, it works fine but with koeo, the pump just runs full duty. I messed up and fried it bout 3 years ago. Quote Selected
Residual Fuel Pump Relay Voltage Reply #16 – August 11, 2007, 01:58:07 AM Quote from: jcassity;167848what is confussing to me is its not actually correct to say "EEC side of coil" because both sides of the fp relay coil end up at the eec either at pins 57&37 or pin 22.The voltage checks are being made with the ignition in RUN. The EEC power relay is picked. The red wire side of the F/P relay goes to +12 volts through the inertia switch, the EEC power relay and fuse link L.Pins 57 & 37 are the +12 volt inputs to the EEC.Quoteto rewind a little, softouch has been able to obtain a different reading than what you have there jeremyb. His reading across the fp relay coil goes to zero in a koeo situation after two seconds,,, yours stays around and trickels down to a full 7vdc.jeremyb made his voltage measurment with the F/P relay unplugged.On my car it settles at 10.6 after drifting around when I check it with the relay out.Trying to buttstuffyze the 7 volts or the 10.6 volts is fruitless because we don't know whats going on inside the EEC.Either voltage is probably normal. Quote Selected
Residual Fuel Pump Relay Voltage Reply #17 – August 11, 2007, 11:20:41 AM Quote from: softtouch;167778 Looking at it with the relay plugged in is the way to go.Absolutely... Otherwise you'll likely be measuring a stray voltage build up... The modern DMMs have such a high input they can send one chasing worms that don't exist... Really something like a old Simpson 260 is more suited for about everything automotive, except measuring o2 sensor voltage...A DMM will be a lot more accurate(for automotive work) IF you add a 5K or so resistor across the voltage input...Tom Quote Selected
Residual Fuel Pump Relay Voltage Reply #18 – August 20, 2007, 01:30:13 AM My procrastination knows no bounds. I pulled the car down from the jack stands on Tuesday and drove it to work for the rest of the week with the original Motorcraft relay. I took a 500 mile trip over the weekend too. Everything works fine. At this point I am chalking up the malfunction to a faulty/incorrect replacement relay. There were two options available from Advance. A SPST and a SPDT. The factory relay has 4 connectors, which would make it a SPST...correct? Quote Selected
Residual Fuel Pump Relay Voltage Reply #19 – August 20, 2007, 02:53:30 PM It would be interesting to know what the resistance of the coils are... Sounds as if the coil may be drawing excessive current...As far a SPDTTD(joke), I've never worried about the FP relays, just plug in a green(factory) skirted one and go... I believe the one in my 5.0 TC was originally inst as one of the relays for the cornering lamps, or was it auto dim???? if I remember... But it ain't orig, as I busted into the orig trying to force a stuck pump to run... Was beside the road, without wire and didn't want to booger up the EEC test plug... Quote Selected
Residual Fuel Pump Relay Voltage Reply #20 – August 20, 2007, 03:19:53 PM I threw out the old relay in a fit of fury. D'oh.I wish I would have kept it to test. Quote Selected
Residual Fuel Pump Relay Voltage Reply #21 – August 20, 2007, 06:19:40 PM Quote from: JeremyB;170558There were two options available from Advance. A SPST and a SPDT. The factory relay has 4 connectors, which would make it a SPST...correct?Correct. Quote Selected
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