Turn key and air, fan, lights are on full. As soon as I turn the key to start the engine, all power immediately goes low. Fan turns off, lights very dim and start does not move. Battery tested well at advanced auto. Turning the key again and nothing. If I wait a while, the car behaves like before, full power until key turned to start. Any help?

 

I'm just guessing here, but it may be corroded or loose battery cables.

 

This sounds like a battery issue. Technicians sometimes make mistakes. I'd take the battery to a different store to test again.

 

Battery one year old. Strange that everything appears to work normally until the last click of the key to start the engine. I tried charging the battery for a few hours. Always measured low current on the charger like it was already charged. Terminals were clean; I rubbed with steel wool anyways. Same outcome. Same outcome when I jump the battery with my truck.

 

If the battery is good and same behavior even with jumper cables hooked up, keep following the power cables and check all connections. This really does sound like a bad electrical connection. It can provide the required current until a high amperage demand hits. At that point the resistance is too high and the voltage drops.

This is the behavior I had on mine when I had a battery clamp failing on my positive terminal. Others have had the cable corrode internally so you can't easily see it.

 

Your battery is very new. Unless your battery has been run flat many times in the last year, the battery is probably fine.

The corroded cables mentioned by the posters above could also cause your symptoms. When you first put your ignition to II, the corroded cables are cool and will let enough current pass to power your lights. When you turn your ignition to III, the starter demands too many amps for the corroded cable to handle. These amps never reach your starter but start heating up the cable. When you put the ignition on II again, the cable is still hot and will not let enough amps pass to power your lights. After some time, your cable cools and enough current will pass to power your lights. To test this theory, you will need a digital multi-meter.

I've attached the pages from the SM. You can start by testing the resistance between the positive battery cable and the starter (red circles). Getting to the starter looks difficult unless you remove battery (1:18 in the linked video). Remember to test the grounds as well (yellow and blue).

If you have never worked with a DDM before, google "using multi-meter to check for resistance". Be sure to note any safety precautions. At a minimum, I would remove the battery. This will be needed to access the starter anyway. I would also wait some time (over-night) after disconnecting battery in case there are capacitors in the system. I think the lights have capacitors but there may be others.

 

I do have a meter to check the cables. I already pull most of the fuses in engine compartment and near drivers side. Before I had this problem, I was getting in the car as I place the key into the ignition. I remember settling into my seat and turning the key quickly through I, II and III positions (definitely more than normal). I heard a click at that time and never got the car to start since. Thanks for your help so far.

 

Also potentiallya parasitic draw on the battery causing it to go lower than needed to start the car. The HFL is a common culprit. Try charging the battery and if it starts, then you'll need to determine the cause of the draw

 

What volts reading do you get on the battery? Ideally you should take the reading after the battery has been resting (i.e., haven't had key in the ignition, nor opened the door or hood) a few hours.

Sorry to return to the battery, but your last post implied this happened suddenly (one day car starts well, next day no start at all). That makes corrosion less likely. Maybe a loose connection, but I don't think a loose connection will explain why lights don't work right after you try the starter.

 

Reading 12.6V across the battery terminals. Reading 12.6V to the under hood fuse box. After turning the ignition to start the car, the fuse box reads 6V (reads -6V across the + terminal battery to fuse box). Seems like discharge of a capacitor. Does this seem like the + terminal cable going to fuse box is corroded?

 

One last voltage reading before moving to resistance readings. Measure voltage across battery terminals while trying to start car. In a healthy battery, the demand for amps will temporarily lower the voltage from 12.6 to somewhere above 9.0 volts.

 

Thanks everyone. Problem is fixed. I cleaned the battery terminals but not the side that clamps all the wires together. After removing the clamp and cleaning everything, it started up. Thanks again.

 

This sounds like a problem I had 2 years ago. Turned out to be the + battery cable. It was corroded internally to the point where it wouldn't conduct enough juice to start the car.
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