1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
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Welcome to Allpar. It does sound like a poor connection or high resistance is causing the 12 volts to drop when a load is placed on it or that the purge solenoid return wire is grounded all the time.
The 12 volts into the purge solenoid is supplied on the Gn/Wt wire from fuse #10 (15A) in the underhood fuse/relay box (PDC). This circuit also supplies the t/converter lock-up clutch solenoid, LDP (leak detection pump), EGR transducer solenoid and fused ign into the PCM. If these other components are receiving good power, then there may be a high resistance in splice S109 or more likely a grounded return wire from the solenoid back to the PCM.
The PCM turns the purge solenoid on and off (a duty cycle)through the ground-side of the solenoid, a Pk/Bk wire. This wire should not read chassis ground, I believe that you have a pinched or rubbed-through wire if this is the case.
The hoses sound OK, one side is manifold vacuum switched by the solenoid and the other comes from the charcoal canister.
The 12 volts into the purge solenoid is supplied on the Gn/Wt wire from fuse #10 (15A) in the underhood fuse/relay box (PDC). This circuit also supplies the t/converter lock-up clutch solenoid, LDP (leak detection pump), EGR transducer solenoid and fused ign into the PCM. If these other components are receiving good power, then there may be a high resistance in splice S109 or more likely a grounded return wire from the solenoid back to the PCM.
The PCM turns the purge solenoid on and off (a duty cycle)through the ground-side of the solenoid, a Pk/Bk wire. This wire should not read chassis ground, I believe that you have a pinched or rubbed-through wire if this is the case.
The hoses sound OK, one side is manifold vacuum switched by the solenoid and the other comes from the charcoal canister.
