Outer Limits 4x4 Board

G'day all

Does any one know of a place to go to get a smaller pulley for a standard 40 altinator... At idle with the lights on, heater on, and wipers on the voltage drops and the right hand indicator stops flashing due to not enough currant .. the altinator was reconditioned last year so is working fine giving me 14 volts at 1000 rpm, but at idle with everything on it drops.. It has been suggested that a smaller pulley so the altinator spins faster at idle could fix the problem....

Any other ideas would be great

I believe you can get a higher output alternator that should fit in the same location as the factory one,

or you could look into getting the orig one rewound so it becomes higher output.

try cooldrive distribution

rewinding wont increase its output at idle nor will a bigger alternator.


before replacing pulleys id be looking at your battery. it should be able to cover power loss from the alternator ie at idle

by putting a smaller pulley on sounds like your fixing a symptom more so than the problem, if you have access to an inductive ampmeter i would suggest indivdually checking the current draw on the components you listed by switching on one at a time to see if any is excessive and if all seems reasonable then you should probly be looking at a higher output alternator and on the other hand it could be a faulty regulator in the alternator starting to show trouble but as popeyehj60 stated the battery needs to be checked probly as a first because they are like an accumulator and should be able to carry a load for a given time. does it crank slow?




cheers jimmy team oh deere 2010

Does it happen as soon as you turn it on or does it take a little bit?, how big is your battery, does it say ca, or cca next to the amps. The battery alone should be able to deal with that load for a reasonable period of time. What voltage does the battery produce after the motor has been off for an hour.

Either or there is a larger problem if the indicator drops completely out, if everything just dimmed a little it would be fine.

Underdriving/Overdriving the alternator SHOULD not achieve anything if the regulator is doing its job, as the regulator is there to regulate current as it is needed, if it does then its only band aiding another problem, and i wouldn't go to the effort for a band aid fix for something to really go wrong 300k's from home with no mobile reception and a whinging mrs quoting "I told you to get it fixed properly" haha.

Have you checked all the fuses, earths and wiring, a bad connection etc will cause everything to draw alot more amps then it should,

Where are you measuring the 14volts from?. What is the voltage dropping to. The regulator might be faulty and is not compensating as it should when there is high load placed on the electrical system (like you are at idle). Even if you have the mother of all alternators, it is not going to produce its rated amperage at any point unless the load on it calls for it, not even if you have the loud pedal out somewhere near the headlight. I really don't think just those things are going to load it so much that it cant power a few indicator bulbs.

When the motor is running power is pretty much supplied solely by the alternator, idleing below 1000rpm the battery will pick up the slack.




Took this bit from a site ages ago when i had a similar gremlin.


Cranking amps is the spec that tells you how much current a battery can produce for 30 seconds at a temperature of 32° F and not have the voltage on any of the individual cells drop below 1.2 volts (7.2 volts for a 6 cell automotive battery). But that figure goes out the window if the battery is not full charged when you measure it.


And thats my novel finished.

Thank you for your novel,... lol
I will attempt to answer each question in order...

!, it takes a little bit for the amps to slowly drop as each item is switched on. meaning a couple of seconds.

2, battery is a extreme duty what ever that means, i have always thought the bigger the better. and racv put this one in.

3, it says cca. Cold Cranking Amps. not ca Cranking Amps

4, Voltage after an hour after the motor has been switched of... unknown.. never tested it i will check today.

5. I have checked all fuses and earths but not ALL the wiring for posotve connection..

6, amperage checked after altinator before battery. at the cableing

7, I suspect the regulator is most likely the problem, but i think the final thing for me to do, seeing how electrical work is not my fort'e. an auto elec will have to be called in...

I thank you for your info and realy apreciate the time taken to give me more info.
cheers to all

yer get someone to pin point the problem, then take the alt off ya self saves ya whatever ridiculous amount they charge these days

cheers berad,

now to consult the finance manager...(missus)... cause i'm running a winch and will be putting a thermo fan on and driving lights. all of which I have already but havent connected them because of the power supply problems..


thanks Eric

Your battery sounds farrrked.
The way we test the batteries state of charge is with a battery hydrometer. A hydrometer measures the specific gravity of the acid solution. The higher the specific gravity, the more charge in the battery. A fully charged battery will have a specific gravity of 12.75. A weak battery will have a specific gravity of 12.50 or 12.25. A discharged battery will have a specific gravity of 12.00 or less. When you check the battery, you need to check each cell. All six cells must have the same specific gravity. If five cells test at 12.75 and one tests at 12.25, you have may have a bad cell. Charge the battery for about 30 minutes and test again. If the low cell does not come up, it's bad and you need a new battery. Some variance is allowed between cells but if it is a large variance, you may have battery problems.

The individual cells can also be tested with a voltmeter. Take a coat hanger and make two lead extensions about six inches long and attach them to the meters test leads. Touch the positive lead to the positive terminal and stick the negative lead inside the cell next to it. It should read about 2.1 to 2.3 volts. Now insert the positive lead in the first cell and the negative lead in the second cell. Proceed down the line until you get to the last cell. Here you will put the positive lead in the last cell and the negative lead on the negative terminal. All the cells should read the same, or within 0.2 volts. If one reads 4.0 or more, you have a shorted cell and the battery is no good. If you get a very low reading or a zero reading, the cell is open and again the battery is no good.

Before you do any battery testing, you need to start with a fully charged battery. If it is not fully charged, then any test results you get mean nothing. So always check the specific gravity before you do anything. Also make sure the terminals are clean and tight.

Try some battery conditioner before you buy a new battery. Got another 12 months out one of my batteries when it started to go.

I'd love to try battery conditioner but as its a sealed (maintenance free) battery....... that wont work

Before buying any new bits and pieces or putting anything into your battery I have a question:

Are you running an external or internal voltage regulator?

The external ones can stuff up, can bounce around and need adjustment, which can be done by GENTLY bending an arm inside. I had this issue with my HJ61 when I first go it.

Also, just because your alternator was rebuilt 12 months or so ago, don't assume that it is still ok. the brushes may be dirty and stopping a decent charge going to the battery, maybe they just put new bearings in and didn't do the brushes and slip rings.

I have also heard of the main power lead from the alternator being old and not letting enough charge through to the battery.

Most battery places will put your battery on a load tester for free, so do this before forking out money for a new one, I would put money on it being one of the above issues, look at that main power cable from the Alternator to the battery.

Flyology,
I had considered changing the leads from altinator to battery as a matter of course to fix this problem but was prepared to wait to speak to an auto elec...

As to the internal or external voltage regulator... you've got me there.... I'm not sure.. as i said earlier.. electrical stuff is not my fort'e. I'm a sheetmetal and mild steel fabricator, so i can build just about anything i want for the old girl but sparking it up with electricity.... no hope..... I just can't get it i have tried to but I'm and electrical idiot... it just does not compute... my brain just won't accept the info so i dont try anymore. It would be very dangerous for any one to get in to my car if i tried that stuff...

But at least I can admit it