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When you say "polarized" do you mean can the wires be swapped between the two large teminals on solenoid? The answer would be no, they can not be swapped.
The negative, or ground, is the whole body of the starter and gets it's connection from the bell housing which has a cable that goes to the battery negative pole.
The positive lead is a big wire that comes from the positive pole of the battery via the alternator. This has a 13mm nut on it.
The little wire, with the 8mm nut, is the "trigger" wire - when you turn the key, electricity goes through this to operate the solenoid (switch) on the starter which turns the starter on (that initial "click" you hear). The starter has this system because the key switch isn't robust enough to handle the amperage the starter needs to turn the engine over.
Take a picture before you take it apart. That way, you will know how to put it back to the way it was before you messed with it.
Thanks. While I do appreciate the wisdom of that suggestion it doesn't actually answer my question. Furthermore, $20 says there's nowhere in the service manual that actually says this, so I doubt RTFM actually applies. Thank you for playing.
I just re-read my post and I would like to clarify what I said earlier. While you may be able to swap the wires on the large teminals physically, electrically they can not be swapped.
Yes I think all the wires you connect to it are positive and it grounds via the bellhousing.
In that sense they are polarized but all +.
I used to wonder if you could swap the internal wiring so a VW Jetta starter would run the right way for a 944 but... now I only have 968s and the starter is different for the 968 6MT.
It'd probably work though, swapping the wires to the brushes.
The negative, or ground, is the whole body of the starter and gets it's connection from the bell housing which has a cable that goes to the battery negative pole.
The positive lead is a big wire that comes from the positive pole of the battery via the alternator. This has a 13mm nut on it.
The little wire, with the 8mm nut, is the "trigger" wire - when you turn the key, electricity goes through this to operate the solenoid (switch) on the starter which turns the starter on (that initial "click" you hear). The starter has this system because the key switch isn't robust enough to handle the amperage the starter needs to turn the engine over.
Offhand, I would have said yes, since the solenoid simply shorts the terminals when the drive is fully extended. But, I took a look at the schematic and found they had done something tricky inside. The solenoid has two coils in it. One works like you would think, taking power from the small terminal, energizing the coil, and grounding through the metal case. The second coil takes power from the small terminal, through it's coil, and grounds through the starter motor windings. When you first turn the key, both coils are on until the big terminals are shorted, at which point the second coil has positive voltage on both ends so it is shut off. This allows the solenoid to pull in hard, then reduce the pull, only maintaining position in order to reduce power to prevent overheating. If you swap terminals, current will always be flowing through the coils in series, which would be a bad thing. Learn something new every day.
08-08-2017, 10:56 AM
Starter Motor Contacts Polarized?
