Test 9 Thermactor Air Diverter Solenoid

Fig.8 - MCU System Wiring Circuit:

1. With key off, disconnect vehicle harness from Thermactor Air Diverter (TAD) solenoid, then connect an ohmmeter across the TAD solenoid terminals. If resistance is between 50-100 ohms, proceed to next step. If resistance is less than 50 ohms, but greater than 100 ohms, replace TAD solenoid.


2. Disconnect vehicle harness connector from MCU, then connect one lead of an ohmmeter to circuit 200 Fig. 8, of the vehicle harness, and the other lead to engine block ground. If resistance is 1000 ohms or more, reconnect harness to MCU and proceed to next step. If resistance is less than 1000 ohms, repair circuit 200.

3. Check TAD valve, solenoids and connections. If okay, check for carburetor leaks, carburetor feedback, bowl vent hose leaks and inline bowl vent solenoid for proper operation.