Charge light

[Citro-nut]

I have a mid 80's KH35 excavator, the charge light rarely goes out. Is has the most basic alternator possible which I'm pretty sure is working. I run it with car batteries, (currently 72ah I think). Am I correct in assuming that the charge light stays on as the battery is oversized and that if I bought a battery same as my B4200 it would be ok?

 

[Nicksacco]

Hello
If the alternator is working you should see around 14Volts from it's output (12 Volt system).
In my experience, a charge light that remains on, indicates that the alternator is not charging.

In many alternators (possibly the one you have) there is a circuit that regulates the current generated and senses whether or not the alternator output is greater than the battery. If not, then the charge light comes on.

Before internal regulators, a separate mechanism was used to accomplish the same thing.

Battery physical size or capacity (amp hours) has nothing to do with it if we're talking about voltage - usually 12V. Now, if you're talking 24 volts, then that is the triggering voltage and the alternator would be appropriate to that voltage (around 28 Volts) but the logic would still be the same.

If the alternator is putting out voltage as indicated, then perhaps there is a wiring problem. Check the wiring to the charge lamp, to the battery, and so forth.

Does that help?

 

[GreensvilleJay]

1st , you need to get the wiring diagram for your KH35 ! The 'charge light' on can be caused by several things and it depends on HOW the 'light' is controlled.
2nd battery size (AH) isn't a factor. Say you use 10,000 electrons to start the engine, alternator only needs to dump 10,001 electron back into battery for it to be charged. analogy.you pull a bucket of water from a bathtub and a swimming pool..you only need to REPLACE that bucket of water and both are full again.

 

[PoTreeBoy]

Check the belt. I was surprised how much, and how quickly, the new belt stretched on my L35.

 

[Citro-nut]

Hello
If the alternator is working you should see around 14Volts from it's output (12 Volt system).
In my experience, a charge light that remains on, indicates that the alternator is not charging.

In many alternators (possibly the one you have) there is a circuit that regulates the current generated and senses whether or not the alternator output is greater than the battery. If not, then the charge light comes on.

Before internal regulators, a separate mechanism was used to accomplish the same thing.

Battery physical size or capacity (amp hours) has nothing to do with it if we're talking about voltage - usually 12V. Now, if you're talking 24 volts, then that is the triggering voltage and the alternator would be appropriate to that voltage (around 28 Volts) but the logic would still be the same.

If the alternator is putting out voltage as indicated, then perhaps there is a wiring problem. Check the wiring to the charge lamp, to the battery, and so forth.

Does that help?

Hi, yes thanks, very helpful. 40+ years a motor mechanic and never did get my head around electrics or electrinics!!
I'll get the meggameter out and check through as best I can.

 

[Citro-nut]

1st , you need to get the wiring diagram for your KH35 ! The 'charge light' on can be caused by several things and it depends on HOW the 'light' is controlled.
2nd battery size (AH) isn't a factor. Say you use 10,000 electrons to start the engine, alternator only needs to dump 10,001 electron back into battery for it to be charged. analogy.you pull a bucket of water from a bathtub and a swimming pool..you only need to REPLACE that bucket of water and both are full again.

Hi, I really need to get a wiring diagram, not sure where though, I'll have a look on the internet.

 

[Nicksacco]

Index of Kubotabooks/Excavators/

This is a good site for diagrams and such but no KH35.

Would the KH36 or U35 listed help? Maybe help get you started tracing wires?