Car won't start, instrument panel goes nuts even after key is removed (*UPDATE*)

[JEDI]

2005 Mazda3, 100k miles

The car worked fine going to work. At lunch, it wouldn't start. I mean, completely dead without even a click noise.

I notice all the gauges going nuts. The needle is moving from one end to the other. I removed the key, same thing happens and the needle in the gauges keep moving

WTF?! thought nothing could happen w/o the key in the ignition?

A coworker jump started the car and it worked fine the rest of the day. I had a load test done on the battery after work and it came up normal.

So, is my car possessed or what?



Update:
Went to Advance Auto and they ran the charging system test.

Battery: Good
Measured: 705CCA, rated for 640 CCA

Starter: Low cranking Amps
voltage 11.3V, amps 11.6A
Starter Amp draw is low with OK starter voltage

Charging system output test: Normal

Drain test: 1.2A -> Suspect
WTF drains 1.2A?

 

[bruceb]

Sounds like bad battery cable connections, or a bad battery. Worst case is bad battery and bad alternator.

 

[medichawk1]

what year is it. Do you have a check engine light on or anything. If its not what bruceb stated it might be the main computer. If the check engine light is not on and the battery cables are clean you may want to go get diagnostic done may cost you 30 or so. They may be able to tell you and if its something expensive trade it in fast lol.

 

[JEDI]

what year is it. Do you have a check engine light on or anything. If its not what bruceb stated it might be the main computer. If the check engine light is not on and the battery cables are clean you may want to go get diagnostic done may cost you 30 or so. They may be able to tell you and if its something expensive trade it in fast lol.

2005 (edited OP)
no warning lights
hm.. battery terminal connection felt snug but w/socket wrench, i tightened it a few revolutions

what do you mean main computer? ecu problem and not loose battery connection?

 

[LTC8K6]

Grounding problems often cause erratic behavior.

 

[thescreensavers]

My parents audi Q7 did that. The battery died and the instrument cluster would be moving and twitching even with the key out. It was related to a weak battery.

But yours passed the test so thats weird.

 

[pcgeek11]

I had the same with a worn out Alternator ( the slip rings were grounded ).

 

[LTC8K6]

Could be the alternator. If you have an Auto Zone or Advance Auto near you, they will check your charging system for free.

 

[JEDI]

Update:
Went to Advance auto and they ran the complete charging system test.

Battery: Good
Measured: 705CCA, rated for 640 CCA

Starter: Low cranking Amps
voltage 11.3V, amps 11.6A
Starter Amp draw is low with OK starter voltage

Charging system output test: Normal

Drain test: 1.2A -> Suspect
WTF drains 1.2A in a Mazda3?

 

[SpatiallyAware]

How old is the battery?

 

[JEDI]

How old is the battery?

bought spring of either 2009 or 2010

 

[SpatiallyAware]

Only thing I can think of is a short causing that drain, or some malfunctioned control unit maybe

Personally I'd disconnect the batt completely, put the batt on a charger and see if it happens again. It's probably going to be a tough thing to track down since it's not alternator or battery