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Re: Alternator problem, could use advise Posted by Ari [Email] (#2847) [Profile/Gallery] (more from Ari) on Tue, 10 Feb 2009 06:00:33 In Reply to: Alternator problem, could use advise, Aerowhead, Tue, 10 Feb 2009 05:20:50 Members do not see ads below this line. - Help Keep This Site Online - Signup |
The light on means that the field coils in the alternator aren't getting enough current. Once the engine revs enough, the alternator gets up enough voltage and the VR can take over, and the light goes out.
Usually replacing the VR does it. The fact that this happens only at the beginning of the day, when everything is cold makes it interesting.
Thought 1 - how did the brushes on the old VR look? Badly worn? You may have chewed up the contacts on the alternator commutator. It makes poor contact. Once things warm up, it makes better contact. Not highly likely.
Thought 2 - replace the BAT bulb recently? The bulb is an integral part of the charging circuit, and it has to be the right value - not just any bulb will do. If it's the wrong bulb, or the right bulb that's tired, it may have a little too much resistance when cold. Once warmed up by the heat of the other bits in the instrument panel, the resistance drops (wrong direction for heat, but this is a weird problem).
Other than that, poor alternator ground, or even loose belts - the alt belts slip when cold, tighten up when warm.
posted by 192.249....
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