Make sure you are using the fully charged battery from your truck. I tried to test mine with an under-powered power supply and only got some clicking.
I then hooked it up to a fully charged battery while pointing it right at my head. Needless to say, it did not just click.
I SAID IT DID NOT JUST CLICK! smile

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission