Posted by Sherman in Idaho [209.33.95.254] on Friday, January 02, 2015 at 20:40:27 :
In Reply to: starter fit problem solved but new starter issue posted by scott 56 [24.130.235.145] on Friday, January 02, 2015 at 18:17:04 :
Put a voltmeter between the starter "hot" post (not the nut or the cable, but the post itself) and the starter housing (not the engine block or the frame, but the housing itself) and have somebody try to crank it. Make sure you're getting plenty of voltage right at the starter before you start "shotgunning" electrical gremlins. The starter load would pull the voltage down a lot from 12 volts, but I'd be looking for 8 or so anyway. Then put the meter between the battery posts (not the cables or the clamps or the body, but the posts themselves) and check again. The DIFFERENCE between the battery terminal voltage and the starter terminal voltage is what you're looking for. I would be suspicious of anything close to or above 1 volt. If you have much difference, then go back and check across the various cables and clamps and see which one is causing the drop. That way you only fix the one that needs fixing rather than randomly working everything over. A simpler test that's sometimes worked for me is to crank a good long while and then feel all the cable connections and see if any one of them is warmer than the rest. If so, that's your bad one.
Since it cranks easily with the plugs out, I don't think it's a tight engine. It could very well be a bad starter, though -- one shorted turn will rob it of a lot of power even though it will spin fast without a load. Sparking at the commutator is often anothger sign of a shorted turn. You can check for binding and rubbing by taking it out and hooking it to a battery with jumper cables. But first do the voltmeter test as I described because if it's a wiring issue that will be the cheapest and easiest to fix.
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