Truck wont crank

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Hanky

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Have you tried jumping the starter yet?
Havent tried that cuz its outside and its. Been 15 degrees all day but if i jump it and it doesnt go what could possibly be not allowing it to go and show such low voltage on the dash mega fuse? Does this one have that?_
 

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Ok so not the pcm b fuse i found a bad fuse for injectors and replaced it but i was thinking that wasnt gonna be the question. What would make my voltage reading on my dash read at 9 volts when the battery is at 12.5 2 good batteries same thing starter and alternator are both at 12.5 too so connections and good and grounds are good cuz it was just running fine what would make it read innacuratly
bad ground would make it read 9v
have you tested for voltage drop and ground test at starter & battery? I am telling you this for a reason, if it drops to less than 10.5, essentially 10.4v and below is all bad for these trucks. ask any good gm tech.
if you have 12v and 0 ohm ground at the starter with the key in the start position then you need to pull the starter
 
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Hanky

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bad ground would make it read 9v
have you tested for voltage drop and ground test at starter & battery? I am telling you this for a reason, if it drops to less than 10.5, essentially 10.4v and below is all bad for these trucks. ask any good gm tech.
Yeah i wish i had it in a building cuz the wind was killer today but ya i need to test for voltage drop and ground again
 

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and that source of bad ground is most likely the battery terminal, take the ground off and wire brush both the battery side and terminal side and re-attach.
but also check the engine block ground strap
 

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you also mentioned the battery gets drained pretty quickly? how fast is your quickly? 30 seconds? 1 minute? 10 minutes?
it's possible your battery is bad also, it can read 12v and have no amps, or not enough amps
will roll a window down and back up with the headlights & heater fan on?
will it run the windshield wipers?
 

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Maybe I missed in the posts, but you started off saying the battery was good. Have you tried the obvious, jumping with another battery or jump pack?

A lot of what you describe would lead me first to bad grounds or corroded battery posts/battery clamps/corrosion inside the battery cables or bad grounds.
But the thing about drop in voltage does make me think of bad grounds or the battery itself failing.

Jump with a good strong battery or jump pack. See if that does it for ya.

You said it has been colder than the balls on a brass monkey. Maybe the cold killed it and happened to be at the moment you changed the LED bulbs.

My 05 Jeep TJ had corrosion inside the battery cables and inside the ignition signal wire to the starter solenoid. I cut back the insulation on the ignition signal wire and it was all crap inside the insulation. Looked OK form outside. New battery cable set took care of the problem on that one.
 
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Hanky

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you also mentioned the battery gets drained pretty quickly? how fast is your quickly? 30 seconds? 1 minute? 10 minutes?
it's possible your battery is bad also, it can read 12v and have no amps, or not enough amps
will roll a window down and back up with the headlights & heater fan on?
will it run the windshield wipers?
Wipers radio heat everything works fine i could turn the radio on loud for 10 minutes so only when i try to start something is wrong but accessories continue to work fine headlights are bright
 

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bad ground would make it read 9v
have you tested for voltage drop and ground test at starter & battery? I am telling you this for a reason, if it drops to less than 10.5, essentially 10.4v and below is all bad for these trucks. ask any good gm tech.
if you have 12v and 0 ohm ground at the starter with the key in the start position then you need to pull the starter

^^ Try this. Measure the resistance from the starter body to the battery negative, it should be very close to 0 ohms. Then measure the voltage at the starter, first while the key is off, then while the key is in the "start" position. Post up what you measured; voltage measurements to 1/10th of a volt.
 
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Hanky

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you also mentioned the battery gets drained pretty quickly? how fast is your quickly? 30 seconds? 1 minute? 10 minutes?
it's possible your battery is bad also, it can read 12v and have no amps, or not enough amps
will roll a window down and back up with the headlights & heater fan on?
will it run the windshield wipers?
It drains .5v at a time as i try to start it
 

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