Jerry's car project

[racer2086]

That's a pretty significant power draw to go from 13v to 10.5 in 15-20 minutes. Unless your battery is bad. Fix the electrical drain first. AngryBear offered spot on advice.

[Timm]

When you charge a battery the terminal voltage will increase immediately - this is called the surface charge and is no indication of the state-of-charge. To find the true terminal voltage switch the charger off and then switch the ignition ON and dipped beams ON for 10 minutes. The battery voltage will now give you an idea of the state-of-charge that can be compared against the table below:



It sounds more like you have a dead battery to me - and time for a new one....

[Jerry Scholder]

That's a pretty significant power draw to go from 13v to 10.5 in 15-20 minutes. Unless your battery is bad. Fix the electrical drain first. AngryBear offered spot on advice.

My apologies for being absent so long; the benefits of being retired and having another 2001 740i with no problems at present. I took the battery in for testing, and as I guessed it was "bad". I replaced it with a Everstart H8. Didn't solve the fuel pump issue, but wasn't expecting it to. I took the fuse out of the Navigation system as it always initiated when the negative cable was removed and replaced. I will update my resistance and voltage readings soon. I very much appreciate your help as always. I'm not giving up and hope you will continue to help as needed.

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I have recently read that a bad crank sensor can prevent a fuel pump from operating. Can resistance be checked on the sensor? So many possibilities with so many answers......

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I have recently read that a bad crank sensor can prevent a fuel pump from operating. Can resistance be checked on the sensor? So many possibilities with so many answers......

[oldroller]

https://www.newtis.info/tisv2/a/en/e...-relay/j2ofjsi

Jerry, a simple check of the circuit. Battery connected, key OFF. Remove the pump connector. Jumper the relay base as noted previously and check for voltage at one
of the wires, should be battery voltage. If not, check your fuses. If still not there is a broken wire to the pump from the relay base.
If you have voltage, unjumper the relay base, reconnect the pump and jumper the base again. The pump should run, even if dry.
If not, check for voltage at the Brown wire at the pump, which is the ground lead. If you read voltage you have a bad ground at X494.
You can backprobe a wire into the brown wire and touch it to a good ground and the pump should run to verify.

X494 is a ground panel, mounted on the right hand C pillar behind the trim above the rear seat back. I've seen corroded grounds from water leaks,
broken wires from stereo refits, etc. Temporarily you could splice a wire with a ring terminal and make another ground to allow you to continue on with
the other issues. Good luck, and carry on, let us know how it progresses.