Very VERY dim alternator light on
#17
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I checked the connections on the back of the alternator and cleaned them off (not very dirty, however. Cleaned a few of the grounds that I had easy access to.
13.7 with only the engine on. With blower, lights, defroster, radio; dropped to 12.8. Turned defroster off, up to 13.4. Seems largely to be a load issue, no?
13.7 with only the engine on. With blower, lights, defroster, radio; dropped to 12.8. Turned defroster off, up to 13.4. Seems largely to be a load issue, no?
#19
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True enough, but I doubt checking/cleaning all the grounding points would detect that. And I'd expect much more electrical woes. I'll look into the rest of the ground points (since I'll have the thing in the air soon), but I'm not overly worried (yet). Wish the earlies had a voltmeter in the cabin!
#20
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If your dropping to 12.8 with everything off i would guess your alternator is on the way out. I would do as Spidey suggested and check your main ground, and Positive terminals. An easy way to check the wire for excessive resistance is take you DVOM with the car running and all loads on put your leads on the neg term and the point on the block where the ground cable bolts. Shouldnt be more than .5 Volts. The Pos you want to check the lead on the back of the Alt to the Pos terminal again only a .5V max or you have excessive resistance in the cables that is consuming power.
Mark
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#21
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If your dropping to 12.8 with everything off i would guess your alternator is on the way out. I would do as Spidey suggested and check your main ground, and Positive terminals. An easy way to check the wire for excessive resistance is take you DVOM with the car running and all loads on put your leads on the neg term and the point on the block where the ground cable bolts. Shouldnt be more than .5 Volts. The Pos you want to check the lead on the back of the Alt to the Pos terminal again only a .5V max or you have excessive resistance in the cables that is consuming power.
Mark
Mark
#22
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I'm sure that's what he meant.
Yes...problem. Your battery should be 12.8. If you aren't above that with all loads on, you battery isn't charging and is making up the difference between what the alternator puts out and what you are asking for....which is why the light is on.
So, as already suggested, you may have a cabling/grounding issue, or the alternator is just getting weak or has a bad voltage regulator. While having a newish VR makes it less likely to be the cause, don't rule it out. They can be and sometimes are bad out of the box.
Yes...problem. Your battery should be 12.8. If you aren't above that with all loads on, you battery isn't charging and is making up the difference between what the alternator puts out and what you are asking for....which is why the light is on.
So, as already suggested, you may have a cabling/grounding issue, or the alternator is just getting weak or has a bad voltage regulator. While having a newish VR makes it less likely to be the cause, don't rule it out. They can be and sometimes are bad out of the box.
#23
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Yes, with all loads on 12.8 is too low. A fully charged battery is 12.6V, your car should be putting out over 13V with all loads on, to keep your battery charged and keep all your loads operating.
Mark
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#25
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Going to take my other alternator in to get rebuilt, may have this one tested at the same time. Doing belts soon so swapping in a new alt isn't overly difficult!
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Have my eye on a possible replacement to keep me in 944-land.
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#30
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Darren, I'm sorry for you! I hope you get a reasonable check from the insurance company. If you need someone in SF to look at a car for you let me know.