304 low voltage charge at idle

[VLmate]

Hi there. My 304 has a low voltage charge at idle (11 volts or so) with a gilmer drive set up. Nobgood cuz at idke it kills my battery. I have read that the pully dimensions with this set up is know to do this. Can anyone tell me a proven solution to fix this, other than reverting back to OEM. Please no offence, but don't offer suggestions or guesses, or I should try this or that, I just want a proven solution, please don't have a crack at me for that.

 

[someguy360]

Increase idle speed or get rid of the junk gilmer drive is your options there, and thats not a suggestion or a guess, it's simply fact.

I went for a Reidspeed serpentine kit, much better design, better looking and it actually works properly.

 

[Dylan kingswood]

I've never had a alternator spit out 11v at idle unless the alternator was dying, I'd be looking at the condition of alternator before worrying about anything else

 

[Deuce]

Does it charge over 14v at a high idle (1500 etc).
If so, pulley ratios are wrong.

You would need a larger crank pulley or smaller alt pulley to increase alt speed at idle.

 

[Immortality]

It depends on the Gilmer kit and pulley sizes. Look at the sizes of the OEM balancer and alternator pulleys and compare to your Gilmer kit and you'll see the balancer pulley is much smaller diameter so that means the alternator is turning much more slowly.

 

[Dylan kingswood]

It depends on the Gilmer kit and pulley sizes. Look at the sizes of the OEM balancer and alternator pulleys and compare to your Gilmer kit and you'll see the balancer pulley is much smaller diameter so that means the alternator is turning much more slowly.

I suppose where a good alternator would have no issues, one failing would drop

 

[Immortality]

Alternators need a certain speed before they will charge. For most cars they will say to check voltage at a certain engine rpm, this is to make sure the alternator is spinning fast enough to put out the required current.

In most cars at idle, if you switch on all the electrical loads you'll find voltage dropping well below the normal rated output of 14 volts.

 

[Deuce]

Alternators need a certain speed before they will charge. For most cars they will say to check voltage at a certain engine rpm, this is to make sure the alternator is spinning fast enough to put out the required current.

In most cars at idle, if you switch on all the electrical loads you'll find voltage dropping well below the normal rated output of 14 volts.

At idle, headlights on, indicator, rear demister, a/c warm on windscreen, radio very low volume:
Mine dips below 11

Don't often find myself in that situation though.

 

[Immortality]

Yup. Cold wet mornings on the way to work could be interesting. Don't have that problem no more...

 

[gtrboyy]

Alternator is underdriven.

Either turn idle up to 1500rpm or find expensive high amperage alternator that will charge at low rpm then try to make it fit & may still not have enough grunt to charge battery.