If a throttle solenoid does not pull in and the power side terminal has 12.5 Vdc but voltage is 0 Vac, what does this indicate?

The scenario describes a situation where there is a 12.5 Vdc reading on the power side terminal of the throttle solenoid, but 0 Vac indicates that there is no alternating current voltage present. This combination of readings suggests that while there is sufficient voltage on the power side, the solenoid is not receiving a complete circuit to function properly.

A throttle solenoid that is open means that the solenoid coil is broken or malfunctioning, preventing the solenoid from pulling in. Hence, there is not enough current flow through it to activate the internal mechanism. The absence of alternating current (0 Vac) aligns with the behavior expected in an open circuit condition, where the solenoid is essentially non-functional, leading to the correct conclusion regarding the functionality of the throttle solenoid.

Other considerations such as a blown fuse would have likely resulted in no voltage on the power side, and an open ground would prevent any operation of the solenoid altogether, so the fact that voltage is present while the solenoid does not operate confirms the solenoid's integrity issue.