The $5 harborfreight multimeters are within a 1/10 of a volt or so compared to the flukes, and I have a $300 fluke, I use the cheap HF meter more, it's close enough for what most will use it for working on their own cars.
Anyways I'm wondering how you know the car charges for a few mins and stops? Usually the PCM will tell the alt to charge, or not charge. Not just random charge and stop, or an alt will charge or not charge, not just do it sometimes.
He hasn't posted for a while..
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Good question. If he’s just going by the dash light, a marginal condition in which the system is wavering around the threshold of good vs. bad charge out of the alternator could explain no light at startup, and light after a few minutes (the example of the brushes being worn down so they’re not pressing very hard against the slip rings, and temperature change can mean the diff. between output being above or below the threshold of dash light/no dash light).
Could also be a bad diode in the alternator so it’s very limited in its current (amps) capability to maintain the average voltage above the threshold to keep the dash light off. That, again, could be a marginal condition wherein one minute it’s above the threshold and the next minute it’s not due to temperature changes as things heat up after startup.
'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs
Last edited by peva; 08-01-2019 at 03:38 AM.