Electrical Manual 2003 GT 4.6L coupe that will not start. Thoughts? Resources?

Manual 2003 GT 4.6L coupe that will not start.

What else should I do to troubleshoot the issue?
What seems to be the most likely culprit?
Who's had this issue before and was able to resolve it / how?

PROBLEM: Key goes in, theft light turns off after 3 seconds, keys turns to start the engine - Nothing happens except for a single loud click. Starter will not run. All dash lights function as they do normally which tells me the car is getting power. There is no check engine light and the car is fully stock... except for aftermarket headlights & LED fog lights.

BACKGROUND/QUESTIONS: I've had no issues with the starter before this, it happened overnight parked outside in -20 Celsius weather (too Cold?)
The morning this happened, the anti-theft system did not recognize the key and would not allow it to turn initially.
See below in "Steps Taken" - a. Solved the key recognition issue.
Can the PATS system disconnect the starter or does it only cut fuel to the injectors?
The car is 20 years old and has 12K Kilometers on it (Are there parts that if unused for long periods of time, don't work right?)

STEPS TAKEN:
a. Turn steering wheel until it locks / tilt wheel to try and start, depress clutch repeatedly while turning key, RESULT: no change.
b. Ensure the emergency fuel cutoff switch is pushed in (behind the driver's side tail light) - (It was). RESULT: no change. I can hear the fuel pump prime (faint whirr) when the key initially turns.
c. Jump the battery; RESULT: no change. Battery was recharged last week and was starting up great until now. Volts read 12.5+
d. Clean battery terminals and visually inspect ground points visible from the engine bay for corrosion (No corrosion): RESULT: no change.

STEPS LEFT TO BE TAKEN:
e. Check clutch pedal is activating the switch in the footwell (Guessing it is or I'd not be able to turn the key to close the starter relay)
f. Ensure the relay and any related fuses are working (Will replace the relay anyway just in case)
g. Replace the Starter assembly (The thing I'm trying to avoid doing on account of that really tricky top bolt and the price tag - this starter has given me no reason to believe it was failing... until now)

PSKSAM2 said:

I was thinking the things you had in e and f, in addition also verifying the wiring to those switches/fuses/relays.

If the click you hear is the Starter relay clicking and it actually is putting 12v to the starter solenoid, then it is probably down at the starter/solenoid, I'd think.

Old school is to tap on the solenoid while keying it a bit, you may get one more start out of it (then choose where you park it mindfully). Hard on our cars with the starter location.

Click to expand...

Thanks for the response.

In case it helps anyone else:

I did eventually try jumping relay no. 4 in the engine bay, which resulted in the same click.
So Ignition and clutch switches weren't the issue (Secondary starter circuit works)

I resolved this by simply replacing the old battery as it turns out it was outputting 480 CCA instead of 590.
In the cold spell we had last week the amperage must've dropped below the starting threshold.
We tried jump starting it with another battery in a different vehicle, but that wouldn't start it even though it turned out to be a battery issue.
Go figure.

Hasn't given me trouble since.



Always double check that the battery works!