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Replaced my alternator today.

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RickB

RickB

Yoda
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I got the replacement and then waited for it to stop raining.
Got it replaced then went to put a bulb in the red idiot light but the socket was melted.

Took one of the other sockets (the Light switch illumination socket) and spliced it in place of the melted socket.
Before putting the bulb in, looking at the volt meter, I could see the car would start but charging would not kick in.

After putting in the bulb it worked properly.
So - another job done. Not quite as well as I would have liked but nonetheless done.

Where does one get these itty bitty sockets & bulbs?
 
What does that socet look like (goes into the small red light with the black plastic tube?) If so I may have an extra I can send in a good ole 42 cent envelope.... I have to did up some stuff. That what you need?
 
Yes Scott, that's the one. It's a small thing about 5/16 inch diameter by 1/2 inch deep. The black tube half melted too! I put what I had together & wrapped it with black tape & stuck it back in the hole. It looks good from the front, but its crappy behind the dash.
Where do you get the little bulbs? I need to get a few of them and couldn't find them at the auto parts place.
 
Thanks Jeff
Looks like I need #615 and LLB281.
Or maybe a #619 - red light assembly?
I guess you just call them to order, I'll get some extra dash light bulbs!
 
Let me get this straight: the indicator lightbulb blows and the alternator stops charging? Is this how other cars are wired too? I would have thought it would have been better to put the lamp in parallel rather than series. Or is there an obvious reason that I can't see for doing it that way?
 
And it is spelled LUCAS.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]the indicator lightbulb blows and the alternator stops charging?[/QUOTE]

No, that's not quite it...

If the bulb blows then the Alternator does not <span style="font-weight: bold">start</span> charging. The sense circuit gets voltage input from the bulb circuit:
The red light comes on when you turn the key to the ON position.
The red light stays on for a moment when you start the car.
The voltage completes a circuit in the alternator from the bulb and shuts off the bulb as the charging circuit activates.

No bulb = No charging.

Unless...
The regulator is also blown in such a way as to cause the alternator to always be in charging mode - which will of course eventually cause damage to the battery and possibly other components.

I'm sure there are other possibilities. :devilgrin:
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Is this how other cars are wired too?[/QUOTE]

I can't speak for all cars, but apparently Nissan's have this 'design' as well. I read all about it somewhere...
 
So, when you took the core in did they bench test it for you to confirm it had problems? Out of curiosity, did you get a good price on the replacement... and a lifetime warranty?

Strictly speaking, on most cars the charge warning lamp isn't wired to the sense circuit, that usually goes back to the battery or the starter solenoid. On some installations the sense wire isn't used (per se) and is simply jumpered over to one of the alternator output (battery) terminal connections. The warning light goes in series with the alternator's field coils. Current flowing through the indicator bulb is used to energize the alternator field coils until the alternator comes up to speed and "self energizes". When that happens, both sides of the bulb are at 12V and with no voltage difference across the bulb, it turns off.

Jeff beat me to the British Wiring link. They are good folks.
 
IMG_2188.jpg

Got it Rick, Its yours if you'd like. Ill slap it in the mail no charge. Consider it a gift for turning me on the the BCF. w/o this place and its wealth of knowledge who knows where Id be! PM me you address if you want it.
 
Bugeye58 said:
https://www.britishwiring.com/CAT16_17.PDF
Jeff
Click to expand...

So I looked at the link - is the bulb we need LLB281? If so, what is the voltage? I keep wondering whether I should test my bulbs before I reinstall the dash - or just replace them outright. I realize it's a low cost thing but don't know how long the old ones - or the new ones last.

thoughts?

BTW - sorry if I'm hijacking the thread
 
JP - It looks to me like something to have on hand, but not worry about until they blow out. They are pretty easy to replace. Yes, it's that LLB281 on my car at least.

Thanks Scott, I really appreciate that more than you can know.

Rick
 
Honda's and Nissan's(back when they were Datsun) were wired this way also. It was a regular thing to wire them up pretty much throughout the industry up to the mid-80's.
 
Just about any 12V light that fits the socket should be OK. The thing just leaks current into the field coils, to provide enough magnetic field for the alternator to get started. In fact, in MOST cases, the alternator will get going without this, since the armature gets magnetized slightly in normal use. This happens in generators, too, and is the reason why you need to "polarize" the field coils when you switch from positive to negative ground--to reverse that residual magnetic field.

To get around this, you could add a resistor in parallel with the light--a power resistor of about 100-200 ohms, five watts--the value is not critical. (Keep it away from other wiring because it may get kinda hot.) Then, if the lamp dies, the alternator will still work. I don't see why the manufacturers don't do this.
 
blkcorvair said:
12-v
Click to expand...

I'm surprised, I would have thought they would step down the voltage to 3V or something - thanks
 
That's a good point Steve. On a similar note, I've had discussions with people adding upgraded alternators to old Jeeps. Depending on which alternator they are implementing, they have been advised to put a 40 Ohm resistor in the circuit to take the place of the warning light. I have used something like this when I've wanted to use a red LED for the warning light. I put a 40 Ohm resistor inline with the power to the field coils and put a dropping resistor and LED in parallel with the 40 Ohm resistor. Wired like this you still get the warning lamp function and you don't have the worries of the bulb burning out.
 
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