[AT] Battery in backwards question

[Steve W.]

Mike Sloane wrote:
> As someone else noted, Larry, starter motors are almost always "field 
> wound" and can only turn in one direction, regardless of the polarity. 
> In addition, those old 6 volt motors work just fine on 12 volts, 
> although they should not be run for more than 10 or 15 seconds. Having 
> converted at least half a dozen Ford, JD, and IH tractors from 6 volt 
> positive ground to 12 negative, I can assure you what I wrote above is true.
> 
> Mike

Most of the starters used for years have been 6 volt units. Just run at 
12 volts for more torque with the newer engines. The easy way to tell is 
to look at the housing. The old large units are 6 volt (common GM and 
Ford units). If you find one of the new small units with gear reduction 
or permanent magnets those are 12 volt starters.
Another place you will find 6 volt items. Many Ford products that used 
dash gauges were 6 volt there was a dropping resistor behind the panel 
to provide a 6 volt source for the fuel, oil pressure and other gauges.

Now days the gauges are 5 volt stepper motor units driven from the ECM.

-- 
Steve Williams
Firefighter,EMT, Fire Police
VanHornesville Vol. Fire Dept