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2000 Harley Davidson FXDX Dyna Super Glide Sport Questions & Answers
My 1999 Harley FXDX twin cam starts very hard. The starter engages but the engine barely turns over, as if it has tremendous compression. The engine will usually catch on the second whirl but if it
You need to do a starter draw test as the starter sounds like it is drawing too much current. Also make sure your battery connections are clean and tight. You might also have your battery load tested. Harley AGM battery is a very good battery BUT even if new may be a weak/bad battery so test it also. Final stop after testing the battery and starter would be, but if it is easier to get done first do a ground voltage drop test to be sure you have a good clean secure starter to ground connection. WHAT IS YOUR BATTERY SURFACE VOLTAGE WHEN YOU START TRYING TO START YOUR BIKE??
VOLTAGE STATE OF CHARGE of AGM Battery
12.7 V = 100%
12.6 V = 75%
12.3 V = 50%
12.0 V = 25%
11.8 V = 0%
If the circuit had a ground resistance all voltage/potential would not be able to be used up because all amperage would not be able to be pushed through the circuit.
The negative or ground circuit can be checked as well to see if there is high resistance at the ground point of a circuit after all of the positive circuitry right up to the point where the electrical current will go to ground. To test the ground circuit place/connect the voltmeter negative lead (BLACK) to the most negative part of the circuit which will almost always be the negative battery post because there is never anything more negative than the negative post of the battery. THEN place/connect the positive lead (RED) to the ground you wish to
check. For example the starter mounting bolt or the starter frame case or the frame in some cases and THEN activate the circuit i.e. turn on the lights, activate the horn, push the start button etc. WHICH will allow you to read the
potential difference or voltage dropped on the negative or ground circuit. This technique is very effective for identifying poor grounds due to hidden corrosion, powdered paint points etc. It is much better than an ohmmeter because even the slightest connection may cause an ohmmeter to give a good reading even though the resistance would not allow a greater sufficient/required current to pass through corrosion or a powdered paint point etc. which will cause a voltage
drop or potential difference in the ground circuit. Since you are going from the negative post of the battery back to the positive post of the battery through the frame there should be a reading of ZERO for a good circuit i.e. no resistance/no voltage loss and again if there is a voltage reading this would be showing voltage/potential lost or dropped
Remember that in a circuit in which electric current will be flowing through a circuit from the battery positive to the ground through the end component, in this case the starter, you need full voltage or potential at the starter post to push electric current through the starter windings to ground to operate the starter which in the circuits we are discussing is/are designed to use twelve volts to do this job. Voltage drop testing tests the voltage applied to the component because it is testing the circuit up to the end component and not the health and serviceability of the end component itself because the entire voltage /potential will be used up or dropped through the starter windings (end component) before the circuit completes and meets the ground. Therefore you could not do a voltage drop test from the positive battery post to ground at the starter mounting bolts because all you would be doing would be bypassing the end component and merely measuring battery voltage. If you wanted to measure resistance or voltage drop in the starter ground circuit you would measure from the most positive point of the ground circuit which would be the starter grounding point, mounting bolts for example, to the most negative point in the negative circuit which would be the negative battery post. If the ground for the starter is good i.e. no resistance the starter circuit would be complete and all of the voltage/potential would be used up pushing the current (amperage) flow through the circuit.
If the circuit had a ground resistance all voltage/potential would not be able to be used up because all amperage would not be able to be pushed through the circuit.
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