Electrical Test

Attach a grounded test light at point "B". Disconnect connector at point "D" and turn ignition on. See Fig 2. There should be no light. If light is present, replace latch relay.
Reconnect connector at point "D", there should be a light. If not, check temperature switch and wiring back to ignition switch.
Disconnect connector at point "D", test light should remain lit. If not, replace latching relay.
Connect test light to temperature switch terminal at point "D". Cool switch below 49°F, light should go out. If not, replace temperature switch.

Fig 1: CTAV System (Below 49°F)
Courtesy of FORD MOTOR CO.

Fig 2: Test Connections for CTAV System
Courtesy of FORD MOTOR CO.