Electrical issue or starter ?

[Avalanche345]

I recently purchased my first Avalanche which will be used mainly for towing duty. Aside from some cosmetic upgrades the main problem that has me stumped is a hard start and electrical drain that occurs while driving. Here's the full story and why I haven't pointed fingers at the alternator right away.

Put in the key turn the ignition and I get a single slow roll as if the battery is dead. turn the key to off position and try again it will start right up. This happens every time. if I drive for a period of time then turn the truck off it seems even harder to start as if the battery isn't being charged by the alternator. and if I turn the truck off without turning off the A/C then all bets off it is a pain to start. One thing I also notice is that the A/C settings are always reset when I start the truck.

The alternator was replaced before I purchased the vehicle and is visibly brand new. I have ruled out the fuel pump issue because I don't get a long roll before starting it is literally as if the battery is dead but if I turn off then try again it starts.

Has anyone experienced this before? Could really use some help on this one.

 

[BainMan]

What is your amperage draw while powered off?

https://www.youtube.com/watch?time_continue=697&v=zdIKNnwEjIs&feature=emb_logo

Battery, wiring and grounds test ok? Go get a free check at your local auto store for the battery/alternator test. Don't rule out the alternator because it was replaced, rule it out because if it tests good.

 

[Avalanche345]

Thanks BainMan will do. Even if the alternator is adding to the problem I don't think it is the root cause because I installed a brand new battery yesterday and same thing. First turn seems like dead battery second turn starts right up. 

 

[ygmn]

If battery charged and up to 12VDC.
Then try to start and if voltage drops to 9.2 or less you have bad battery or lose cables bad connection.

IF second attempt battery voltage is more...then first time I would look at wires and or starter solenoid and/or starter motor.

Use external Multimeter on battery terminals not the trucks gage.

 

[EXT4ME]

Have the battery LOAD tested.

 

[Avalanche345]

If battery charged and up to 12VDC.
Then try to start and if voltage drops to 9.2 or less you have bad battery or lose cables bad connection.

IF second attempt battery voltage is more...then first time I would look at wires and or starter solenoid and/or starter motor.

Use external Multimeter on battery terminals not the trucks gage.

Thanks YGMN, will do.