Hi I'm diagnosing this for my mom who has been stranded twice and subsequently had two batteries needlessly replaced.

She has a 2006 Sante Fe with aftermarket command start. Intermittently neither the key or command start will turn the engine over or actuate the starter solenoid. The accessory position provides no power to anything.

I can guarantee that only the battery has power and connection under the hood is tight and clean. If she has it towed, it will end up starting and the dealership will replace the battery for no other reason other than she's a overly trusting woman.

Does anyone know what relay picks up when the key is turned to accessory? Does this relay also need to be picked up to get to the starter solenoid? Does the immobilizer circuit interfere with this relay?

I'm all for supporting battery manufacturers but this should have been fixed by a competent tech by now...Can anyone help out?

Thank you!

 

I would make sure myself that the battery posts and cable terminals are clean.
Have seen where a bad terminal at the starter solenoid would prevent the starter from cranking
However, you don't have power in the accessory mode.

Try using a multi-meter. One end on the negative battery post.
The other on the engine block
And have someone crank engine over.
If the meter reads battery voltage then bad ground
Clean and redo the ground at the chassis (battery ground)

Check fuses. Fusible links.

 

Thanks for the reply. The car did start and is en route to my place. Sounds like a ground, here's hoping!

 

This may or may not be the cause of the problems the vehicle is experiencing.

For some reason, some vehicles are not "happy" with aftermarket add on devices..
Not knowing your level of expertise , if you can manage to try it , it could maybe save you some grief.
Many times , disconnecting the aftermarket device gets rid of the dead battery or no start problem.
Since no cause has been determined and it is a, Pain, when you cannot get the vehicle to start, it might help eliminate the aftermarket device even temporarily.
If it gets rid of the problem,or not, at least you will have eliminated one of the leading causes . Some of these devices will work for a period of time , then cause all sorts problems. So even it it never had a problem before , things change and a hard question to answer is , "It worked before so how could it be the problem"?
Consider disconnecting it and see it the problem goes away,