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only 6.5 volts to the fuel pump


chatham

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im only getting 6.5 volts to the fuel pump. 6.5 volts to the inertia switch. my gut tells me its the ECM am i missing something?
 


adsm08

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Check power into the relay.
 

chatham

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it is a 1990 BII sorry for leaving that out. dont have too much experience in trouble shooting electrical so thanks for bearing with me on this.

just to let you know i have already put in a new relay and i still get 6.5 volts at pump. tried to check the voltage to the relay by removing the connector and checking the pins there. the drawing that i have in the manual indicates that red is the hot but i get no voltage there. checked all the others and now voltage so im doing something wrong. key is in the on position.

whats next?
 

adsm08

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Wrong wire, You are interested in the black/yellow wire. Should have power all the time, regardless of key position.
 

chatham

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checked that and no voltage there. sounds like you probably know this but here are the wires into the relay plug

brn
blk ylw
red
grey ylw/tan ylw combined into one location
 

adsm08

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How exactly are you checking voltage? You can't have nothing on that black and yellow wire but have 6.5 V to the rest of the system.
 

chatham

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pulled connector off of relay and put multi meter lead into it and the other lead to ground
 

adsm08

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Try taking a piece of wire, stripping and twisting one end, and sticking that into the pin instead, then putting the meter lead to the other end of the wire. Meter leads are hard and don't always make good contact. Wire strands flex and bend and do the job better.
 

adsm08

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Ok, with the relay out and matching whatever your original conditions were check for power at the inertia switch.
 

chatham

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with the connector off of the switch i checked both red and orange wire against ground. no voltage
 

Earl43P

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Red will only have power with the key in Run and the EEC relay has to be good for that to happen.

BK/Y should have power ALL THE TIME from fuse 1.

Verify you have both of those voltages at the fuel pump relay socket.
 

unoleisu

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Hate to throw this in so late but...Did you make sure your ground is good? That kicked my ^$$ not long ago. ALWAYS check it.
 

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