Alternator Warning Lamp Circuit Question

Quote:

---

Originally Posted by dom14

snip...
sense wire have connection issues or the fuse on it dies and the alternator puts out some 18+ volts.
That kills the alternator dash warning light(assumption on my part).

---

Your assumption is wrong, a sense wire fault won't blow the lamp

When the alternator is running on all 3 phases the lamp has approx zero voltage drop which is why it goes out, 12, 14 or 18 volts doesn't matter

So you want to run a double redundancy system? Come on , do you really think a manufacturer would do that, unless it was for the luxury or military markets?

Breakdowns keep the economy ticking over:)

Quote:

---

Originally Posted by the evil twin

Your assumption is wrong, a sense wire fault won't blow the lamp

---

I believe you. But, you still have to give me the facts behind your conclusion. Otherwise, I'll only keep annoying you here. ;) :D

Quote:

---

Originally Posted by mudnut

So you want to run a double redundancy system? Come on , do you really think a manufacturer would do that, unless it was for the luxury or military markets?

Breakdowns keep the economy ticking over:)

---

No argument there mate. :D

The "typical altenator circuit" I downloaded from internet and uploaded here suggest two separate pins(wires) for warning lamp circuit & trigger/field/exciter circuit. So, I was guessing it's been already out there. It's that I just don't have it, 'cos I gota GQ?! :D ;)

Quote:

---

Originally Posted by the evil twin

Your assumption is wrong, a sense wire fault won't blow the lamp

When the alternator is running on all 3 phases the lamp has approx zero voltage drop which is why it goes out, 12, 14 or 18 volts doesn't matter

---

Yeah, that would mean the regulator puts out "-18 volts"(on the lamp circuit) [or is it +18V] and that would roughly give -6V to the warning lamp(-18V+12V), so the warning lamp would come on, but nowhere near enough to cook it(I'm obviously speculating here with loose knowledge).

Yeah, my argument was apparently based on a wrong assumption as well as poor understanding.(obviously forgetting the base fact of how the warning lamp circuit works)

Does this mean mudnut's worry about alternator lamp blowing is NOT likely to happen?!!

If I disconnect the sense wire, would the dashboard alternator warning light come on?!

a little knowledge can be very dangerous

I ain't worried about it. Just thought you would like to know about it, cause that is the sort of great guy I am:)

Quote:

---

Originally Posted by dom14

snip...
Yeah, that would mean the regulator puts out "-18 volts"(on the lamp circuit) [or is it +18V] and that would roughly give -6V to the warning lamp(-18V+12V), so the warning lamp would come on, but nowhere near enough to cook it(I'm obviously speculating here with loose knowledge).

---

Nope...

If the Alt is putting out 18 volts at the Reg Diode Pack then that is also the voltage that will be (WRT earth or -ve if you prefer) at the B+ and therefore the Battery positive, the Ign cct and everywhere else in the vehicle.
There will not be anywhere in the vehicle supply buss that is at 12 volts so there is no 18-12=6

Quote:

---

Originally Posted by Makka

a little knowledge can be very dangerous

---

ROFL... and a lot can be bloody frightening