Help please, weak crank when starting

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Apr 8, 2012 | 12:02 AM

Xemeth

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Help please, weak crank when starting

OK, so I was putting the finishing touches on my 2002 Mustang with an LSX/4L65E in it. So I went to go start her up.

Problem is, I have a very weak crank that won't last for more than a second or so. I did a voltage drop across the battery to the positive cable on the starter, and it has 14V (hooked up to jumper cables on a running car), but when I crank it it drops down to 7.9V. I figured bad starter drawing too much voltage, so I try the starter from my buddy's Silverado (5.3). Same thing.

I'm using a PSI stand alone harness. I have the crank signal for the starter connected directly to the crank signal wire coming out of the ignition switch.

I'm just kinda at a loss here. Maybe it's because it's 1 am and it something stupid I'm gonna find tomorrow, but I figured I'd come here to ask for some opinions.

Thanks, hopefully I posted enough info.

Apr 8, 2012 | 12:23 AM

LS1TA_956

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From: Laredo

A ground, try grounding the engine by hooking the negative jumper cable to the ground of the batt. And the other end the block and try it

Apr 8, 2012 | 11:21 AM

jmoli42572

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I have had a bad battery that even if you had jumper cables hooked up to it you still could not get it to start. I think it was a bad battery post. Also had grounding problem like stated above

Apr 8, 2012 | 08:35 PM

Pop N Wood

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Clean your battery posts and charge up the battery before trying again.

Apr 9, 2012 | 12:23 AM

ls1nova71

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From: Liberty, MO

I would try another battery. Voltage is one thing, amperage is another. It might show 14 volts but without sufficient amps it isn't going to start.

Apr 9, 2012 | 01:14 AM

rotor vs. piston

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vvvvvvvvvvvv

and also test your battery. Had a similar issue and ran a ground straight from the battery to a bolt for the starter and has been a dream since.

Apr 10, 2012 | 12:25 AM

Xemeth

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It was a brain fart on my part. I completely forgot to ground the motor to the chassis. I did that and it cranked right over. Something I should have known, but I'll attribute it to it being the middle of the night and me being exhausted, lol.

Thanks for the help, guys.

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