Second Alternator Woes (Gwyn Lewis)

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wiltshire landyman said:
is the lamp vital??
Click to expand...

I guess not but it's nice to know whats happening.

wiltshire landyman said:
can u just not piggy pack of the exciter wire of the 1st alternator?
Click to expand...

I don't think so (but I stand to be corrected). I used an ignition switched relay to feed a 12v supply from the 2nd Battery to the 2nd alternator - if you piggy back, you'll have a feed from the 1st Battery determining what the 2nd alternator does.

I may be totally wrong. :eek:
 
auf_wiedersehen_pet said:
I guess not but it's nice to know whats happening.



I don't think so (but I stand to be corrected). I used an ignition switched relay to feed a 12v supply from the 2nd Battery to the 2nd alternator - if you piggy back, you'll have a feed from the 1st Battery determining what the 2nd alternator does.

I may be totally wrong. :eek:
Click to expand...

I think it is dependant on the alt. some need a fixed resistance, some don't as far as i can tell.

some can self excite and not need any, some are three wire some are two.

I think with these alts it'll work fine with no bulb or resistance and just a 12v connection. I have zero clue if it'll shorten the life of the alt long term.

i'm not sure what you are doing, but fyi, you can run two alts with a single battery. It'll just provide more current for gadgets.

Also, two batteries can be charged from a single alt and you can also wire two batteries in parallel to provide more cca and capacity

SteNova said:
5w load is needed, it doesn't have to be a lamp
an led won't work
Click to expand...

Do you know what will happen long term if no load is added? as these alts seem to work fine with 12v (which is why the led probably works)
 
Yesterday I actually got round to shortening and tidying the wiring. Tightening the nut when putting the main wire back on I heard a crack - more like the sound of cracking plastic than electrical sparks. Now I've got no charge :) 2nd alternator light glowing like mad!!

Any suggestions?

:(:(
 
Going from bad to worse now! :mad::mad::mad:

Came out of work and it's as a flat as a witch's tit. No lights, central locking, dash, etc. However, the second battery is fine!

So, faulty 2nd alternator leads to main battery flattened.

RAC called. Jumped. Starting fine but no output from alternator 2. Drove over to my old mucker, Jerry Lewis (Lewis Land Rover Specialists 07972 150814) and it started fine over there. The quick option for 5:30 in heavy drizzle was to remove the HD red cable from the 2nd alternator so it can be removed from the equation. Neither of us can see how it could be anything else and nowt else has been touched.

Any thoughts guys and girls?
 
i'm not sure of your full setup, do you have 2 completely seperate alts, warning lights, and batteries. or do you also have something else linking them?
 
trax said:
i'm not sure of your full setup, do you have 2 completely seperate alts, warning lights, and batteries. or do you also have something else linking them?
Click to expand...

Hi. Yep. 2 Batteries. 2 Alternators. 2 Warning lights. All seperate.

Numerous comments have come in through my build thread so have a gander in there first.

:D:D
 
Dude.

Not sure if you know, but Gwyn Lewis has just started making 2nd alternator wiring looms.
Not sure if they're actually on sale yet but a picture of the finished product has just been put up on his Facebook page this morning. :)
 
Ok ill explain,
the excite wire give's the inner coil of the alternator enough power to create the electromagnetic field to start the alternator generating power.

If you give it too much power it will be to hard to turn the alternator from standstill and this is why they use a bulb, ... the resistance created by the bulb reduced the current (power) down to a nice level to start spinning the alternator and also gives you indication that its drawing power.

once the the alternator starts generating power it then takes over powering the the inner coil and becomes self sufficient. The light will then go out.

The LED most likly had to high resistance to start the alternator off
 
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