2007 GX 470 No start, hear clicking, headlights and dash lights flash when trying to turn it over

[neilsen100]

Looking for any help diagnosing a non start issue. Battery is charged. turning the key to ignition I hear a consistent clicking and simultaneously the dash lights and head lights flash on and off. Engine never turns over. Has been driving fine for past 5 years I've owned it, about 157,000 miles.
I'm ignorant about how to determine if a starter is need, if it is a fuel pump, or something else entirely. Any thoughts are appreciated as this is a daily driver.

 

[neilsen100]

Also, did connect a ScanGuage. While key is in "On" position, but obviously not running, ScanGuage says no codes

 

[HomersCanyonero]

I had a similar issue last month, but it was my battery was a little low. Lights and radio would turn on, but not enough juice to start.

I plugged a jump starter and it started.

In my case, it was battery running a little low.

But if you are it’s not battery….then not sure how you could troubleshoot the starter or fuel pump or alternator

 

[Rednexus]

Most likely it is the battery. A battery can give you close to 12V but still be damaged internally and not have enough oomph to start the motor, despite being able to turn on headlights/radio/etc. Those items flickering off when trying to crank is usually a dead ringer that you have a battery issue.

You should be able to remove the battery and take it to most any auto parts store for a free load test (where they'll check the cold cranking amps and battery health). If it fails, you'll need a new battery. Note that the battery may need to be fully charged before they'll test it. I personally keep one of these around, for regular battery health checkups: Amazon product ASIN B0B42JS1FH
If the battery is relatively new you may have a parasitc drain causing this (just had to fix that issue myself).

 

[kwkshift]

It could also be a bad connection to the battery. I'd ensure the terminals are clean, the cables are cleaned and the main grounds are good. There could be a good enough connection to provide ~12v to the gauges, lights, etc., but not enough to allow the needed current to be drawn to start the engine.