NEED HELP!!!!

[Shannon L Haynes]

Got a 07 silverado. (Newer body style) when i turn key forward, my headlights and gauge lights flash off and on, door locks cycle unlock to lock, dinger constantly chimes, heater/ac off an on. Clock resets to 12:00. Ive replaced the following. Both battery cables with my own clamps as i read the factory crimp is bad. Replaced 175 amp mega fuse. Added bigger grounds everywhere possible. Replaced fuse box. Replaced ignition switch. Tested alternator. Came back good. Data logged it and voltage fluctuates between 12v to 14.9v. Has the following codes u0100, u0121, u0140, p0325, p0573, and p1682. Yes ive researched each code and know/ understand them. Cant find fix. Extremely irritating.

[Doug_Scott]

You still have a dirty/poor connection somewhere. There is a bulkhead connector that will sometimes corode and cause this type of issue. Generally when you get the clock resetting to 12:00 when you turn the key on it simply means there was a drop in voltage to under 6 volts momentarily. Most common cause is a bad battery connection for that.

 

I am not sure if I am reading your message correctly regarding battery cables. Did you replace the entire cable, and put your ends on them, or did you check the connections at each end, and then replaced the battery end of the two cables?

 

Stock cables have been known to not be 100% copper core. Some have aluminum/copper core, and they do not play well together. Take a good look at the other end of the cables(not battery end), and try to look under the insulation near the crimp for any white powdery crap. If there is any, replace the enitre cable with a premium cable that comes with proper ends moulded on.

 

You need to put a voltmeter across the battery terminals, and have someone else turn the key so you can see the voltage action. It is best to use an analog volt meter, as opposed to a digital one. The analog will respond to any quick drops in voltage that a digital may not let you see.