I have found that the solenoids on the A2's require FULL battery voltage to pull in (in addition to moving freely/lube). If they do not pull in, you can manually push it in with power on and it will stay, than you can start the truck. This has happened to me on two trucks and with a new solenoid. Once the batteries are up to full voltage, no issues. If I let the truck sit for several weeks without use, the voltage drop will be enough to cause the problem again.
On a truck I bought from GL and recovered, the batteries were dead-dead. It literally took two weeks with my chargers to bring the batteries back. But once I did, no more issues with the solenoid. During the time I was bringing the batteries back, I simply removed the solenoid and used the cable stop. The truck would crank and start fine after 48 hours of battery charger time but again, it took weeks before the solenoid would work.
By the way, if it does not pull in and it stays that way with power applied, the solenoid will get very hot, eventually burning up.