I replaced the starter solenoid about four months ago since it was occaisionally failing to activate the starter which could be remedied by tapping the solenoid. Upon replacement the car started fine until recently the symptoms reappeared and then the solenoid failed completely (checked by running lead from battery + terminal to solenoid terminal #50). This seemed unusual so I checked the voltage on the solenoid lead wire (disconnected from solenoid) with the ignition switch in the # II position (run) and 12.3 volts was present! This, I assume, would result in the solenoid activating during the "run" position which would probably burn it out, or worse destroy the starter motorand/or pinion gear. So before installing a new solenoid I continued to explore the source of this apparently incorrect voltage (by the way, out of curiousity I checked the solenoid lead on my 85 and 86 240's at the #II ignition switch position and they were 0 and 4v respectively). I have checked all of started wire circuit, including the starter switch (pulled it out and tested all of the pins to see if voltage is being supplied from terminal 30 to 50 during #II position, which it is not, as well checking to see if 12v is present in the #III position, which it is) and found no shorts with other circuits supplying 12 V. However, what I have found is that terminal 30 of the Jetronic computer is supplying 12v to the solenoid wire circuit in the #II ignition switch position; my understanding is that terminal 30 on the Jetronic is the cranking signal input and should only receive 12v when the ignition switch is in the #III (start) position so that the computer allows spark to be supplied to the engine. So, I suspect something is wrong with the Jectronic unit; however, when I activate the test code box I get "111" indicating the the unit has no faults. This appears to be a fairly simple circuit with no other possible routes for 12v to be supplied to the starter solenoid except from terminal 50 of the ignition switch or from terminal 30 of the Jetronic. Has anyone else run into this problem? Is it really the Jetronic unit that is defective?
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