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Alternator - will it fit?

losh1971

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We been around since forums & car mags were popular...I'm old man (early 40's)
You're a spring chicken, my B-day in a few days, no need to say how old I will be..... lol
 

Immortality

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If you are getting 14.4 volts at the alternator but only 12 volts in the system you need to find the voltage drop. Get a cheap multimeter and start measuring voltages across different points in the electrical system.

I'd start with all the main earth/supply cables and then start working from the battery back towards the main relay panel.

The stock charge cable isn't ideal, Holden spec'd the cable for average load, not peak load and then add 25years + of wear and tear etc. The V6 models had a bad habit of burning out the charge cable on the back of the alternator.
 

losh1971

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If you are getting 14.4 volts at the alternator but only 12 volts in the system you need to find the voltage drop. Get a cheap multimeter and start measuring voltages across different points in the electrical system.
Get something half decent the cheaper MM's are too inaccurate. An $80 from Jaycar will be ok.

The V6 models had a bad habit of burning out the charge cable on the back of the alternator.

Is it worth upgrading the V6 alt charge cable? What BS cable would you recommend, 6BS?
 

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Get something half decent the cheaper MM's are too inaccurate. An $80 from Jaycar will be ok.



Is it worth upgrading the V6 alt charge cable? What BS cable would you recommend, 6BS?

Check the charge cable at the back of the alternator and look for corrosion and brittleness. If it's all green and the copper is discolored it's worth replacing. Can't remember what size it is but it's worth going up one size.
 
D

Dean1985

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The charge cable isnt the standard one. I had at one stage relocated the battery to the boot (and back again). The auto elec hadnt seen the car (was a phone convo) and he said some just had a larger charge cable.

I had an elec issue a few weeks back which had me inspecting all wiring, connections and a new bosch 85 amp alt. So i can confirm the terminals are in good nick. As are the earth's and the body earths are more than adequate size.

I have a Fluke 325 MM which has been assisting me in my fault finding.

This afternoon after work i checked battery voltage before starting. 12.4v.

I started the car with the dash in test mode and the voltage showed 14v. A mate was using the mm across the battery which showed 14.5 at idle.

Lights, blower fan, engine fan on and the voltage dropped down to 11.8 at battery at worst.
11.6 on the dash.
Turn the engine fan and blower off and things looked normal again, about 13.6 on the dash.

So standard accessories dont hurt it. If the idle was brought up to about 1500 we saw the voltage come back up over 12.5.

There was about 200milli volt loss between battery and dash readout. I see that as not bad.

So we think the issue is just an underprovisioned charge system.

My question now is, would a 120amp push enough juice at idle compared to an 85amp? Im aware they dont put out their potential at idle and thats where the magic needs to happen to get things good.

Cheers for all the replies guys
 

losh1971

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Seems odd that it drops so much. I know mine is only V6 with two stock fans but I run 400w amp drawing 25a or more at level 40 with amp turned right up, twin 55w HID's, lights on high beam and run both thermos with AC on most of the time and never had any issues with not getting enough power, even on idle. I know the thermo fan upgrade on the V8 draws some extra current but that much I am surprised at.
I'd be inclined to load test the battery. I previously had issues with a slowly dying battery. People on here said can't be battery as once alt kicks in everything should be fine but it wasn't.
 
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Dean1985

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We are actually talking about grabbing a battery tester tomorrow at lunch haha.

Can anyone confirm if an alt provides its full output at idle?
 

EYY

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We are actually talking about grabbing a battery tester tomorrow at lunch haha.

Can anyone confirm if an alt provides its full output at idle?
No it will generally provide full (regulated) voltage at 1200rpm+.
Check your charge sense wire very thoroughly if you haven’t already (although added resistance typically means the alternator overcompensates and provides higher output, it’s good practise to check).

May be worth trying a different regulator too.
 
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