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Re: Yup - Time for Action! Posted by Ari [Email] ![]() ![]() In Reply to: Re: Yup - Time for Action!, Oldsaabguy, Wed, 28 Apr 2004 11:43:43 Members do not see ads below this line. - Help Keep This Site Online - Signup |
It may be a bad VR - always a possibility, as the VR is a wear item. However 'continuity' is an interesting thing.
The bulb has been specially selected to provide just the right current to the alternator to get the field coils working. Too little, and the alternator won't work. I believe it's a 1.2W bulb, which means it passes more current than a smaller wattage bulb. At 12 volts, that's around 12 ohms. So you could have a poor connection on the order of 2-3 ohms, and that will drop the current flow a lot.
The trouble with continuity is that both a 1 ohm circuit and a 100 ohm circuit are continuous. The other problem is voltage - if you have no load on the circuit, 12.0 volts on one side of a 100 ohm resistance will give you 12.0 volts on the other side. Only when you stick a load on the other side of the resistor do you see the voltage drop.
Take the thin wire that goes to the alternator and ground it to chassis, something other than the alternator body. The light should be bright. If it isn't bright, then (1) you've got the wrong bulb in there, or (2) there is still a poor connection. With that wire grounded, move up the wire with your meter, measuring the voltage. See where it drops unusually.
If the bulb glows bright when you touch chassis with the wire, try touching the case of the alternator. If it's dim, then the grounding between the alternator and chassis is bad. If that is bright, then I'll say the VR is shot.
posted by 192.249....
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