Yet Another Start-up Issue

[TheArchaic1]

Ok guys, I have a 2001 LS V8. This morning I am in a rush to get to work, and when I get into my LS and put the key in and turn it, I get everything but the engine turning on. The PATS light is lit solid, and I get a "Check Traction Control" message on the dash. The battery is brand new, but the car fired right up with a jump.

I have a voltmeter on my radar detector, and in the morning it says that I have 12.3 to 12.5 volts, yet when I go to lunch halfway thru the work day and fire it up I have 13.9 to 14.2 volts.

I know that there is a voltage drop from the battery to the detectors input, but this is starting to get ridiculous. Any help or ideas would be awesome!!!

 

[joegr]

With the engine running, your electrical system voltage should be between 13.8 and 14.5 volts. When you turn the engine off, the battery voltage will quickly drop to 12.6 volts, the natural voltage of the battery. 12.3 is probably still okay, since there probably is some drop from the battery to the detector, and the voltage display on the detector won't be 100% accurate anyway.

The big question for you to answer (and you will probably need a voltmeter for this) is what is the battery voltage when you turn the key to the start position? A quick and dirty way to get an idea is to turn the headlights on and see if they dim when you turn the key to start. If they do, you may have a battery problem, or (more likely) you may have a loose electrical connection, probably at or near the battery.
If they don't dim, then it's probably the starter relay, the ignition switch, or the starter itself.

BTW, if you do get a voltmeter, the battery voltage (at the battery) shouldn't go below 9 volts while the starter is engaged.

 

[TheArchaic1]

I think I got the problem fixed. All I did was turn off the auto-headlamp delay and the voltage went up to 14.0 at startup figuring in the drop of about .2 to .4 volts from the battery to the connection.

 

[Outkast]

my neighbors LS did that too. A new bat. fixed it.