Ihave a 06 tundra that starts in run position priodicaly.When this happens when shut off and sits for a period of time it drains the battery

Did you let the vehicle sit for 30 min. before testing ? Modules need to time out (go to sleep - power down etc.. How are you testing ? Have a ammeter inline with battery negative cable and negative battery post . Have any doors open ( door switch closed ) Key out of ignition ? How much current ? 50 milliamps max !

Looks like you have a "parasitic current draw" not likely the bad ground. Use an Amp meter, set it on 10 amp setting, shut off everything inside the car, make sure nothing is plugged in in any power outlets. Shut all the doors. Remove the battery positive terminal and hook up the amp meter between the positive battery terminal and battery positive cable. see what is the meter reading. The normal draw is 0.05 amp and less. If the draw is more then that you have a draw. The way to pinpoint the faulty part that draws the current is to, start removing the fuses one at a time and monitor the amp meter to see when the current drops to normal. As soon as that happens look at the fuse and see what part is that particular fuse feeds. most likely you find the culprit.

Anti theft is active.

You need the automatic throttle control system scanned.

If she turns off the radio and the battery stays up, it is easy enough to fix. But I do not think enough power is used to completely discharge the battery overnight.

Intermittent shorts are very hard to find, so you really can not blame the repair facility for not being lucky enough to find the problem. It is really a hit or miss situation to catch the defect when it occasionally happens.

There are a few cheaper parts to guess with as causes. A bad ignition switch may not turn off when the key is in the off position. Relays for the ignition, fuel pump, or electric cooling fan may not release when the ignition is switched off. Rear defrosters will silently drain the battery.

What you are looking for is something which does not blow a fuse, yet uses enough current to kill the battery. Bad diodes in the Alternator can easily drain a battery, have the Alternator tested for Diode function.

Can't say how much power the Alarm system is suppose to use. It is one of the few systems which operates with the car turned off. Again, whether it can draw that much power in a short period of time is questionable.

You can get free wiring diagrams at Autozone.com after registering your car. They also provide Relay box diagrams.

You can safely use an Ohmmeter on the circuits when the battery is disconnected. The idea is that the positive and negative wire leads are suppose to be separate. If you find a positive wire that is letting the Ohmmeter ground to the negative side, you have found the short. The 2 charges do not mix in things that are turned off. It means that the positive wire is touching the frame somewhere or powering a lightbulb or electric device instead of breaking a fuse.

I hope my solution helps you. Since you paid someone to fix this and some States require at least 30 days for repair Warranties, take it back.

the controllers in the vehicle draw a small amount of power even if the car is not running, probably enough to drain a battery over a long period of time, when you store a car it is recommended to charge the battery at least once a month

Something is draining the battery, Is the battery drained after sitting over night or within driven miles. If it drains over night power is being puled from a source, or the voltage regulator inside the alternator is pulling the power and draining you battery.

Check the connections on the battery,It sounds like one or both may be loose.

6.5 quarts and then check it after running it a bit and shut down for 5 minutes.

most likley you have a bad starter next time it happens try tapping on starter when your son holds the key in the start position