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No power whatsoever

Tiny
SANTIABEYTA1266
  • MEMBER
  • 2006 HUMMER H3
  • 3.5L
  • 5 CYL
  • 4WD
  • AUTOMATIC
  • 157,000 MILES
I have no power when turning the key after doing an alternator change and also a big 3 upgrade.
Sunday, September 29th, 2019 AT 5:56 PM

27 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Welcome to 2CarPros.

Exactly what is a big 3 upgrade? Also, does anything work such as the head lamps?

Let me know.

Joe
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Sunday, September 29th, 2019 AT 6:35 PM
Tiny
SANTIABEYTA1266
  • MEMBER
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The big 3 upgrade is upgrading the 3 main charging wires. And there is absolutely no power.
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Sunday, September 29th, 2019 AT 7:44 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Welcome back:

If you have nothing, either you lost power to the under hood fuse panel or ground. Something should work even if the alternator was replaced. See pic 1 and 2. Since nothing is working, this is where I would start.
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Sunday, September 29th, 2019 AT 8:04 PM
Tiny
SANTIABEYTA1266
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Thank you so much man! I think you narrowed down the problem good enough to solve it. Thanks again!
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Sunday, September 29th, 2019 AT 8:48 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Welcome back:

You are very welcome. Let me know what you find.

Take care,
Joe
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Monday, September 30th, 2019 AT 7:02 PM
Tiny
SANTIABEYTA1266
  • MEMBER
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It was the wire you were talking about. Can I ask one more question?
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Monday, September 30th, 2019 AT 7:04 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Welcome back:

I hate to ask this, but we are trying to keep the threads specific to one topic. If the question is related, I would be happy to continue on this thread. If it is something different, would you please start a new thread. I hate asking that, but it becomes more beneficial to others when it is done that way. I will watch for a new post for you if it is something different.

I hope you understand.

Joe
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Monday, September 30th, 2019 AT 7:40 PM
Tiny
SANTIABEYTA1266
  • MEMBER
  • 15 POSTS
No sir it is related. I was just wondering how to tell if the megafuse is bad?
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Monday, September 30th, 2019 AT 8:55 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Welcome back:

What to do is check for power at both ends of the fuse. If there is power only at one side, remove the fuse and check it for continuity. Here is a link that explains how to check one:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Here are a few links you may find helpful:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

Let me know if that helps or if you have other questions.

Take care,
Joe
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Tuesday, October 1st, 2019 AT 5:10 PM
Tiny
SANTIABEYTA1266
  • MEMBER
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Thanks again sir.
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Tuesday, October 1st, 2019 AT 5:39 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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You are very welcome. Please let me know what you find or if you have any questions, feel free to ask.

Take care,
Joe
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Tuesday, October 1st, 2019 AT 5:45 PM
Tiny
SANTIABEYTA1266
  • MEMBER
  • 15 POSTS
My megafuse was out. Replacing it solved the problem.
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Tuesday, October 1st, 2019 AT 6:34 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Welcome back:

Great! Glad to hear you got it fixed. It took a lot to blow that one. LOL

Let us know if you need help in the future.

Joe
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Tuesday, October 1st, 2019 AT 7:54 PM
Tiny
SANTIABEYTA1266
  • MEMBER
  • 15 POSTS
  • 2006 HUMMER H3
  • 3.5L
  • 5 CYL
  • 4WD
  • AUTOMATIC
  • 160,000 MILES
Vehicle has power but will not crank. This problem started with me and a few friends trying to replace my alternator. In the process of doing so, we ended up having to take the fuse box and battery off which was fairly easy and non troublesome. We then upgraded the thickness of the the 3 main power wires (more of an add on, less of a replacement) and when we hooked everything up there was no crank and many different fault codes on my dash. The anti-theft light also comes on as a solid light and then turns off after about a minute. When turning the key to the crank position the dash lights just shut off (could be considered dimming) and then they turn back of right after.

Any help will be greatly appreciated. Thank you so much!
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Wednesday, October 30th, 2019 AT 5:59 PM (Merged)
Tiny
AUSTIN5432W33
  • MEMBER
  • 7 POSTS
Check all your grounds and make sure everything is connected correctly and that no fuses are blown. If everything is connected correct and still no crank try tapping the starter with a screwdriver while someone else tries to crank. If it does replace starter. Send me some pictures if you want and I'll see if I can help more
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Wednesday, October 30th, 2019 AT 5:59 PM (Merged)
Tiny
SANTIABEYTA1266
  • MEMBER
  • 15 POSTS
First thing in the morning I will send pictures.
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Wednesday, October 30th, 2019 AT 5:59 PM (Merged)
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,320 POSTS
Hello,

If I can jump in here. it sounds like the battery is weak. To be sure lets run down this guide to confirm the failure:

https://www.2carpros.com/articles/car-battery-load-test

Please run down this guide and report back.

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Wednesday, October 30th, 2019 AT 5:59 PM (Merged)
Tiny
SANTIABEYTA1266
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Okay, after getting a brand new battery, still no crank no start.
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Friday, November 1st, 2019 AT 12:48 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Welcome back:

If the battery is good, I need you to confirm there are no loose or corroded terminals on or from the battery. When you say the lights dim or go out, that is either a weak battery as Ken mentioned, a loose or corroded connection, the starter is bad, or the engine is locked and the starter can't turn it.

What I need you to do is check if there is power to the starter. On the starter you will have a large wire straight from the battery positive. Is should have 12v all the time. There will also be a smaller wire which only gets power when the key is in the start position. I need you to confirm that is what is happening. If it is getting power, remove the starter and have it bench tested. Most parts stores will do it for free with hopes of selling a new starter. If it passes the bench test, see if you can turn the engine at the crankshaft using a socket and breaker bar to confirm it can turn.

Here is the link I was referring to. Take a look through it and let me know if it helps or if you have other questions.

https://www.2carpros.com/articles/starter-not-working-repair

I need to know one more thing. You replaced the battery, so it should be good. When you said the lights go out, does everything electrical stop for a short time and then start working again? If so, take a look through this link:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

Let us know what you find.

Take care,
Joe
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Saturday, November 2nd, 2019 AT 11:29 PM
Tiny
SANTIABEYTA1266
  • MEMBER
  • 15 POSTS
I can answer a few of these questions now.

1. Brand new battery terminals but they are possibly just aren't that good (already ordered some nice ones) there is also no corrosion anywhere.

2. The electronics only dim out for maybe half a second and then come back to full brightness. I do hear a click but it does not come from the starter. Maybe a relay click of sorts?

3. The starter makes no clunk or any types of noises.

I should be able to test the starter tomorrow morning so we will see how that goes and I will update you then.

Thank you so much for your efforts to help me out!
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Sunday, November 3rd, 2019 AT 12:52 AM

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