'03 CTT No start, dual batteries good

[vrichmd]

I got in my '03 CTT this morning and it would not start.  I put the key in, got the normal lights and sounds and the starter wouldn't turn over at all.  I can hear what I assume are the battery relays.  Both batteries are fairly new, but I charged anyway, same result; tried to jump start, same result.  I drove the car yesterday and no issues.  The starter has been working perfectly, no dragging, or slow starts at all.  Does this sound like the starter? Has anyone had the starter go bad suddenly with no prior warning?  Any suggestions would be greatly appreciated before I have it towed to the shop.

[Loren]

"If two batteries are fitted to the vehicle (main battery and backup battery), these are connected or disconnected to the bus bar in the power distributor through a relay. The switching of the two batteries is controlled independent of the load management (function is integrated in the vehicle electrical system control unit). The starter relay of the 2nd battery is actuated parallel to the starter relay. That means for every start the starter is supplied from both batteries. The backup battery is disconnected from the vehicle electrical system when the engine is switched off and then supplies just one consumer, the vehicle electrical system control unit."

 

Unless those old batteries have been load tested there is no way to know if they can handle starter loads.

I would still get at least one new battery and give it a try.

[vrichmd]

Where is the power distributor located?

[vrichmd]

FIXED! I had to take it to my mechanic and he was puzzled after both batteries tested fine and removing the starter and it bench tested fine.  Ultimately, he cleaned and tightened the power connection at the starter and the connection at the power distribution box and this fixed the problem.  There was some corrosion on the starter connection and this connection came from the factory without a lock washer and wasn't completely tight.  It did last 17 years, though.

[Loren]