These old starter motors use a field coil for the stator magnet. To
reverse direction, you have to reverse the polarity on either the field
connection or on the brush connection, but not on both. If you reverse it
on both, the motor will continue to run the same way and will even run on
alternating current. It's the same style of motor that an electric drill
uses.
If the truck runs an extended time with reverse polarity, it will screw up
the condensor in the distributor since these are usually only made for one
direction polarity. When this happens, the truck will run bad or not at
all.
I bet the temp and gas guages wouldn't have worked on this truck too
because they need the correct polarity.
I think the new starters on newer GM cars (the ones the size of a big soup
can) use permanent magnets for the stator to save weight. If so, these
will run backwards if the battery is hooked up backwards, but you will
probably fry all the electronics first before the engine turns.
Blessing every minute I worked on these things with my dad when they
weren't such oletrucks (and I wasn't so old either.)
Bruce Kettunen
57 3200
Mt. Iron, MN
>
>
>When I bought my 59 GMC it was hooked up backwards (positive ground) BUT it
>still ran. I drove it home before I even picked up on this fact. Always
>amazed me that it would start when hooked up backwards?
>
>Blaine Dumkee
>59 GMC 9314
>Fort Smith NT
>Canada
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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