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alternators driving me nuts...

Started by Punchy , Aug 11 2017 03:39 PM

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12 replies to this topic

#1 Punchy

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Posted 11 August 2017 - 03:39 PM

I bought a new bosch alternator from Bursons which is meant to be the compatiable direct replcement for the v8 hatch.

No biggy. Shelled out the couple odd hundred bucks and wack it on...gilmer drive of course too

Didn't see it at first but its got 2 blade terminals at the back plus the battery charge terminal. Right, wacked the signal wire lead on the right termal eventually and sweet ..its charging. here now lies the problem.

I upgraded the ignition system. New recurved electronic holden distributor and relay to get direct 12 volts from the battery to coil and distributor. Using the old ignition coil wire to trigger the relay.. easy..yeah..

Heres the problem. With the relay in the system, ive just detected that 4 volts is being shoved up the signal wire and back feeding into the electrical system so when I turn the key off ...it keeps running and it wont shut off. just enough volts to keep the relay active.

Any idea's ? .. swear I'm gonna put a match to the thing soon ..FFS

This was all done chasing weak spark and shitty firing..

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#2 hanra

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Posted 11 August 2017 - 03:59 PM

Diode time for you it sounds.

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#3 Punchy

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Posted 11 August 2017 - 05:04 PM

That should already be in the system tho isnt it ?

I even just fininshed getting a good secnd hand bosch 55 amp alternator to try it and its still the same..so its the car..not the alternator as to say...

I hate electrical..

Any gurus.. i forget more than i remember

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#4 hanra

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Posted 11 August 2017 - 05:15 PM

Did you fit a diode already? It's not there from the factory.

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#5 Punchy

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Posted 11 August 2017 - 05:16 PM

o..but i have found this thread on in relation to it... have to fit a diode somewhere it appears..

http://www.gmh-toran...urn-engine-off/

Edited by Punchy, 11 August 2017 - 05:18 PM.

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#6 hanra

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Posted 11 August 2017 - 05:22 PM

Yeah just find your excoriation wire off the back of the alternator.

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#7 _hutch_

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Posted 11 August 2017 - 05:55 PM

Yep a diode in the exciter circuit will fix your problem,what is happening is the alternator is sending 12 volts out of the spade terminal that is connected to the light wire,when you turn the key off the warning light allows enough through to hold the relay in,connect the diode with the bar towards the alternator

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#8 Punchy

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Posted 11 August 2017 - 07:26 PM

this diode is this something in a prepackage type thing ( like a fuse holder) that i can connect a couple of spade or what ever electrical connectors too or a just a flimsy bit of wire with a dohicky in the middle ?

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#9 hanra

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Posted 11 August 2017 - 07:35 PM

Not really.

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#10 _hutch_

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Posted 12 August 2017 - 10:41 PM

What I do is to fit into the lume away from the alternator,and tape it all up so as the main output cable supports it,solder it if posible

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#11 _hutch_

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Posted 12 August 2017 - 10:52 PM

Effectively the diode is like a non return valve,it allows the warning light current to flow to the alternator but blocks it from coming back up the warning light circuit back feeding your ign system,if you go to any auto electrician shop and ask for an exciter diode you will be set,we used to sell them for around $3.00,if you go to jacar you will need about a 3 amp one to be robust enough