[76C10Stepside]

Found a Haynes S10 manual I forgot I had and ran the following Alternator and Ignition Coil tests today. Opinions, comments and suggestions welcome!

Note: When I started the engine (last driven last night), it had good cranking power, took several revolutions to fire (typical on this truck when cold), but also felt like there was some resistance to turning over (kinda "thunky"), but otherwise no unusual noises (not even the alternator noise I've been hearing often).


Alternator Tests:
1. Voltage across battery terminals with engine OFF. Should be 12.5 to 12.8 V.
RESULT: 12.65 (OK)

2. Engine running at high idle (1250 rpm, COLD). Should be 13.8 to 15.3 V.
RESULT: 14.91 V (OK). Note: Heat was ON for this test, but voltage in range.

3. Engine running at high idle (1250), heat, lights and radio ON.
RESULT: 14.84 V (OK).

Note: Did not try revving the engine, as it was COLD and already idling at 1250 rpm, and wanted to be sure I got all the tests run. GOOD ENOUGH?


Test Old Ignition Coil (per the Haynes manual):
1. Book says resistance should be "very high or infinite" (on "high" scale). Does not say, but assume this is the primary coil test. Says to test on the
RESULT: "1" (Ohm meter did not respond, stayed at 1) on 2000k Ohm setting (high on my multimeter). Seems to be an open circuit when no power supplied to the coil. OK?

2. Books says resistance should be "very low or zero" (on "low" scale).
RESULT: 030 (on 200 ohm setting, calibrated at 0). Is that a PASS?

3. Book says should "read high, but not infinity" (on "high" scale).
RESULT: 008

Test NEW Ignition Coil (to compare to old one):
1. "1" (Ohm meter did not respond, stayed at 1), same as old coil.

2. 026

3. 001

Notes: I assume the first coil test is to verify that the primary coil circuit is "open" when no power applied to the coil? For this test, the leads were on the top/left terminal (with the two plugs at the bottom).
This is my first time testing an HEI ignition coil.
Since the coil test instructions are rather vague (no specific values given), and there was very little difference in readings between the old and new coils, I assume the old coil is still GOOD.