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My wife drives a 91 Accord, ~275k miles (still gets 35mpg, uses no oil. Amazing).
Anyway, the other day the battery light started flickering on when she pushed the clutch and came to an idle. It goes off when she starts driving again. The alternator is a reman and is about 3 years old. I put a multimeter on the battery with the ignition off, doors closed, no accessories on, etc. and it measured ~12.5. I then started the car and performed the same reading: 11.8. Doh! The alternator isn't charging... I pulled it and had it tested: OK. I had the battery tested: OK.
The battery cables are about a year old, and there was no corrosion. All the fuses and fusible links were OK. My Toyota has a fuse that, when pulled, will essentially disable the output of the alternator...it doesn't appear that the Honda has one. As far as I know the belt isn't slipping (it's a newer belt, doesn't appear shiny and doesn't have any cracks).
I'm going to put it all back together tonight, but was wondering what else to check. I'll probably try taking a reading directly off the alternator terminal to ground, as well as taking some readings at various RPMs...
:25: Maybe it's time she gets that new shiny car she has been looking at :) |
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| porcupine73 |
| Are there any plugs / connectors on the alternator and do those look good? It's also possible if it is an intermittent problem that jostling the alternator around to take it out for testing maybe made it look like it was ok? I mean if the alternator 'tested ok' and you measure the voltage on the alternator output stud with reference to the alternator case and it isn't above roughly say 13 volts I don't know how it could be testing good? Unless you have some massive power draw in there somewhere? |
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quote: Originally posted by porcupine73
Are there any plugs / connectors on the alternator and do those look good? It's also possible if it is an intermittent problem that jostling the alternator around to take it out for testing maybe made it look like it was ok? I mean if the alternator 'tested ok' and you measure the voltage on the alternator output stud with reference to the alternator case and it isn't above roughly say 13 volts I don't know how it could be testing good? Unless you have some massive power draw in there somewhere? | |
Thanks for the reply.
I haven't tested the output directly at the alternator yet, but will tonight. I agree though, if that isn't showing 13-14 volts, something is wrong. There is a connector as well, which looked ok from a cursory inspection. I'll have to pull the electrical schematic out to see what the wires there do. I'm assuming there is a ground, possibly a hot wire and a sense wire of some sort.
The massive power draw is possible. If nothing else turns up I'll start pulling fuses to see if it can be isolated to a circuit. I might have the alternator tested again at another shop to make sure the first test was accurate. |
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| porcupine73 |
| You mentioned the alternator being replaced with a rebuilt a few years back..........was it from a parts store? Those alts are notoriously junky. |
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quote: Originally posted by porcupine73
You mentioned the alternator being replaced with a rebuilt a few years back..........was it from a parts store? Those alts are notoriously junky. | |
Yep, I know. It's hard to spend $400 on a part for a car that's worth $1500 though. :) |
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| porcupine73 |
| Well granted that hehe......just saying, part store alt could be suspect. Not sure if Honda offers their own remanufatured alts? |
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quote: Originally posted by porcupine73
Well granted that hehe......just saying, part store alt could be suspect. Not sure if Honda offers their own remanufatured alts? | |
They do. Best I've found online from a dealer is $280 but with shipping and tax it gets close to $350. Local dealer was quoting $370.
Piece of junk parts store price: $100. Even if it only lasts 3 years, it's a better deal. We probably won't have the car another 3 years anyway :) |
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| porcupine73 |
| That's true. The parts store alts usually have 'lifetime' warranties anyway. |
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| neutron |
Worn brushes. Common on the N-D alternators used on these cars. They'll test "OK" because the rectifying diodes (etc) are OK. With worn brushes there will be a weak field and this is what causes the charging system light to flicker, and the intermittent low output.
Change the alternator or the brushes. Brush change is a DIY job if you are meticulous... no special tools needed.
Last time I did this, my local parts store actually had them in stock, and so did the stealer. They were $3.95 at the part store and $4.95 at the stealer. |
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quote: Originally posted by neutron
Worn brushes. Common on the N-D alternators used on these cars. They'll test "OK" because the rectifying diodes (etc) are OK. With worn brushes there will be a weak field and this is what causes the charging system light to flicker, and the intermittent low output.
Change the alternator or the brushes. Brush change is a DIY job if you are meticulous... no special tools needed.
Last time I did this, my local parts store actually had them in stock, and so did the stealer. They were $3.95 at the part store and $4.95 at the stealer. | |
It doesn't have the OE alternator in there. Swapped it out 3 years ago. I was too tired to mess with the car last night, so I'll probably play around tomorrow. |
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| nipper |
you can NOT test an alt off the car. It has to be spinning at 1800 rpm or higher with a full load for a valid test.
You need an Alt. There is no standard for what is a rebuilt alt. For all you know it may be the opriginal volt regulator and it only had a bad brush or diode.
Buy a cheap alt you get your moneys worth. Lately there have been a lot of junk rebuilds out there.
nipper |
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