A/C Pressure Switch (LS400)

Install A/C pressure gauge set. To access pressure switch , remove right headlight. Pressure switch is in line with A/C receiver. Turn A/C selector switch to OFF position. High side pressure should be 142 psi (10 kg/cm² ) or less.
Disconnect switch terminal connector. Using a DVOM, check for continuity between switch terminals No. 2 (ohmmeter positive lead) and No. 3 (ohmmeter negative lead). See Fig 1-29.
Turn A/C selector switch to ON position. High side pressure should be 192 psi (13.5 kg/cm² ) or more. No continuity should exist between switch terminals No. 2 and 3. If A/C pressure switch continuity is not correct, replace switch.

Fig 1: Cooling System Relay & Switch Terminal ID (LS400, ES300 & GS300)

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Fig 2: Cooling Fan Relays No. 1 & 2 (LS400)

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Fig 3: Cooling Fan Relay (GS400)

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Fig 4: A/C Clutch Relay (ES300)

Fig 5: A/C Pressure Switch (LS400)

Fig 6: A/C Clutch Relay (LS400)