Forum Discussion
maillemaker
Sep 26, 2019Explorer
Given that the OP’s chassis is a 1990 E350 it’s almost guaranteed to be a simple 4 post constant duty solenoid. AKA Ford starter solenoid.
Usually mounted on the drivers side behind the battery it has 1 heavy wire to the house battery, 1 heavy wire to the chassis battery, 1 small wire to an ‘ignition run’ wire and the last wire to the emergency start button. Nothing complicated or mysterious at all.
My 1990 E350's house charging circuity is a bit more complicated than that. I believe there are 2 solenoids involved. Plus what looks like some kind of bus bar or fuse bar kind of thing. I'll take a picture this weekend.
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