Defogger Relay
WARNING: This page is about a different car, the 2002 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect defogger relay. Using an ohmmeter, check for continuity between terminals No. 1 and 2 on defogger relay. See Figure. If continuity exists, proceed with test. If continuity does not exist, replace defogger relay. Check terminals No. 3 and 4 of defogger relay with ohmmeter for continuity. If continuity exists, replace defogger relay. If continuity does not exist, proceed with test. Using fused jumper wires, attach terminal No. 1 of defogger relay to battery voltage and terminal No. 2 to battery ground. Using an ohmmeter, check terminals No. 3 and 4 of defogger relay for continuity. If continuity does not exist, replace defogger relay. If continuity exists, defogger relay is operating at this time.