Last month we discussed relay theory. Now we’ll apply this information to an air conditioning control circuit with three relays. The relays control the cooling fan motor, condenser fan motor and A/C magnetic clutch. Marlowe Peterson’s “Cool Honda A/C Troubleshooting Tips” in the May, 1999, issue of Import Service covered Honda air conditioning operation with detailed practical troubleshooting tips based on his firsthand knowledge of pattern failures. In this article we take a strictly electrical point of view of a 1990 Honda Accord air conditioning control circuit, with an emphasis on relay troubleshooting techniques.