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My 2004 Denali XL with one year old 925 cranking amp gel…

Customer Question
My 2004 Denali XL...

My 2004 Denali XL with one year old 925 cranking amp gel cell top of the line battery would not start after 150 mile trip. After I jump, I drove straight to parts store, where the scanner read voltage regulator failure. I was in a remote location 150 miles from home. Drove him without stopping engine. Voltmeter fluctuated from 11-15 volts, including with headlights on. I just completed replacing alternator. After trickle-charging for four hours, it won't start, and turning the key on producec flickering lights, flickering gauges, and involuntary circuit activations (like drivers seat control begins moving seat forward and backward.) In general, it seems like the entire electrical system is shorting when I turn on the switch. I know I corrected connected the battery cables and correctly connected the alternator cable and the ground. What should I do? I am planning to have someone try to jump me in the morning and, if it starts, take it to Autozone, where I bought the alternator (and the one year old Duralast battery, and have them scan it to look for codes. I guess I am concerned about two things: Did driving with the voltage regulator malfunctioning for 200 miles damage the electrical system? How do I find out? And did it destroy the one year old battery? If the car does not jumpstart, I will have to tow it, but it's Saturday and no one is likely to work on it (that I trust) on Saturday morning in San Antonio. I would like your thoughts on the nature of the problem.

Mechanic's Assistant: Have you checked the fuses? Have you checked the bulbs?

There are no bulbs out. I have not checked fuses, but which fuse would prevent the battery from starting the vehicle if the battery is accepting a charge?

Mechanic's Assistant: What is the model of your '04 GM?

Yukon Denali XL with 6.0 liter engine and 145 amp alternator.

Mechanic's Assistant: Are you fixing your Yukon Denali yourself? What have you tried so far?

Yes. i changed the alternator because the voltage regulator failed according to the scanner at O-Reilly's. I then trickle charged the battery for four hours and the light shows green on the trickle charger. The headlights turn on when I move the ignition switch to the "on" position and the display lights turn on and begin to flicker a bitt and gauges flicker and the system makes strange sounds as though it is "shorting" but that is simply a layperson observation. When i actived the ignition, it clicked like a vehicle will click when inadequate charge exists to start an engine.

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

The car has almost 230,000 miles and I have not had the "gremlins" in my electrical system at all (like i read about on the forums) prior to this voltage regulator failure. The vehicle has functioned extremely reliably in all respects. this origina

Submitted: 3 months ago.Category: GMC
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Answered in 10 hours by:
3/24/2018
GMC Mechanic: Dan, ASE Master Technician replied 3 months ago
Dan
Dan, ASE Master Technician
Category: GMC
Satisfied Customers: 2,111
Experience: Dealer Auto Technician. ASE Master Certified, 15 years of experience
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Hello my name is***** am a Master Technician and I am glad to help you. I am reviewing your question now, and will reply shortly.

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GMC Mechanic: Dan, ASE Master Technician replied 3 months ago

If the vehicle starts with a jump then you need to have the battery tested. Also make sure you battery cables are tight.

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Customer reply replied 3 months ago
The vehicle does not start. Removed battery. Tested. Produces 12.8. Not the problem. Re-installed and connected cables to terminals. Tested voltage. Only produces 2.8. Cleaned positive terminal connection. There was some corrosion on the plate but not the wire. It now appears fine. Cut plastic cover off of it to check the wire. No corrosion in filaments. I then cut the plastic cover off the negative and found corrosion in the filaments at the end. I guess I will go to AutoZone and buy a new terminal connection for the ground and try that, because something unknown is causing a reduction once the terminals are connection to the wires. It has to be in the connection to the terminals on the battery, right? Everything in the vehicle is off, so I don't see how anything could be draining voltage from the battery that would cause a ten volt reduction in the voltage just from connecting the battery to the vehicle. What am I missing? What else could be wrong other than a bad connection at the battery that could cause a ten volt reduction just from connecting the battery?
GMC Mechanic: Dan, ASE Master Technician replied 3 months ago

Corrosion causes high resistance which will lower voltage. Sounds like you are on the right track by replacing the battery connections.

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GMC Mechanic: Dan, ASE Master Technician replied 3 months ago

I am contacting you because this question has not been closed or rated.
This question will automatically time out after 7 days. Please let me know if you have any questions so I can help more.
A 3 star or higher rating would be greatly appreciated.
Thanks.

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GMC Mechanic: Dan, ASE Master Technician replied 3 months ago

A 3 star or higher rating would be greatly appreciated.
Thanks.

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