No Start, No Dashboard Lights, Battery good.

Relay issue? Voltage regulator issue? Ignition Switch issue?...Problem: 2006 Sequoia. If I let the vehicle sit for a week or so without starting it.. (Sometimes, not all the time) when I go to get in the vehicle I will notice that there are No indicator lights on on the dash and when I try to start it... there is NOTHING.. Not even a little click of the starter relay. I check the voltage on the battery with a millimeter and it shows low but not that low... a typical reading will be 12.2 volts. If I connect my battery charger and only have it connected for less than one minute I can then disconnect the charger and the vehicle will start under its own power. Suggestions?

 

I've cleaned and re-tightened the connections on the battery (Several Times)... I bought a new Costco Interstate Battery (January-2022). I have checked for a parasitic draw on the system (inline amp meter) Yes, there is a slight drain. (Nothing over 0.05 amps).

 

I think you need new connector terminals

 

Connector terminals...? Are you referring to the battery connection terminals? such as this:

 

Yea, also the body ground

 

Have you experienced these connectors causing such a condition? It is defiantly something I can address. In addition to cleaning (wire bushing) the connections to the battery (both neg and pos). I also removed the Negative cable where it connects to the vehicle body. I wire brushed the connection area and re-bolted down the connection..... even though there were no signs of corrosion.

 

I would do the following:
Disconnect the ground from both the battery and the ground point on the truck. Measure the resistance between the negative terminal and the connector that you disconnected from the truck body - should be next to nothing.
Have the battery load tested at an auto supply store. Even a new battery can go bad prematurely, and even an Interstate.
Measure parasitic current several times over a period of time when the truck is off, leaving the ammeter connected. This works best if you have a simple analog ammeter. There may be something that draws current at times other than right after shutting the truck off.
Another way to rule out parasitic current draw is to disconnect the battery when you park and will not be driving for several days. Then, reconnect right before starting.

BTW, Welcome from LA (Lower Alabama)!