Mode Control Circuit
- Remove logicon switch assembly from vehicle. Connect a 12-volt battery to terminals "L" and "d". See Figure. Connect a jumper wire between terminals "I" and "L". Connect a resistance of at least 1000 ohms between terminals "D" and "L". See Figure. Using a voltmeter, verify voltage is approximately 12 volts between terminals "D" and "L". If voltage is not as indicated, replace logicon switch assembly.
- Connect a jumper wire between terminals "C" and "L". See Figure. Connect a resistor of at least 1000 ohms between terminals "A" and "L". Using a voltmeter, verify voltage between terminals "A" and "L" is approximately 12 volts. If voltage is not as indicated, replace logicon switch assembly.
- Connect a resistor of at least 1000 ohms between terminals "d" and "D". See Figure. Using a voltmeter, verify voltage between terminals "D" and "L" is less than one volt. If voltage is not as indicated, replace logicon switch assembly.
- Connect a resistor of at least 1000 ohms between terminals "d" and "A". See Figure. Using a voltmeter, verify voltage between terminals "A" and "L" is less than one volt. If voltage is not as indicated, replace logicon switch assembly.
- Check for continuity between terminals specified in LOGICON SWITCH ASSEMBLY CONTINUITY TEST table. If continuity DOES NOT
exist in any test procedure, replace logicon switch assembly.
LOGICON SWITCH ASSEMBLY CONTINUITY TEST
| Conditions |
Terminals |
Continuity |
| Vent Switch |
J-L |
Yes |
| Bi-Level Switch |
G-L |
Yes |
| Heat Switch |
H-L |
Yes |
| Heat-Defrost Switch |
E-L |
Yes |
| Defrost Switch |
F-L |
Yes |