Military Lightweight Forum

24v generator won't charge batteries its drained my batteries twice, i replaced the generator with another and its giving the same problem so i don't think its the generator. Any ideas

JIm well you did ask, lots of ideas here:

https://www.militarylightweight.co.uk/r ... generator/

Clive, thanks for that but its made my head hurt

Jim

Jim it is important to establish a diagnosis before replacing components that may in themselves have more faults that you introduce that complicate the issue. Besides the components you remove may be ok but you can never trust them again.

In your ownership did the system work once?

How do you know it is not charging?

Have you measured the voltage on the batteries & not seen an increase as you rev?

If you have a non-transistorised system with two ammeters what does the vehicle ammeter show?

Does the charge warning light go out when you rev?

Or is it a case of the batteries going flat over a few days despite originally being fully charged?

Hi Clive

The system has been fine with no issues, until now.

I've measured the voltage of the batteries and it doesn't increase as I rev the engine.

the charge light comes on but won't go out

I only have one ammeter on the shunt box but that hasn't worked since I've had the Landrover some 9 years now.

it takes a while but the batteries will go flat despite being fully charged.

any ideas is very welcome, im working my way through the fault finding on the generator manual that you sent.

Jim

Jim the ammeter in the shunt box is only for the radio batteries if fitted & besides it only shows charge going in not discharge.

It is important to establish whether you have a continuous leakage of current when the vehicle is unattended. Do you have a battery isolating switch in the negative lead to chassis? If you do always ensure it is left off.

With everything turned off It would be worth disconnecting the negative earth lead then connecting an ammeter between negative and chassis. Preferable an analogue ammeter (ie needle as opposed to digital) on the highest amp range which is likely to be 10A or 1A see if there is any needle movement, then each time disconnect then reconnect the ammeter on progressively lower ranges. Even a small drain of 10-100mA will significantly drain your batteries.

Bear in mind that the negative output from the generator is not earthed it only achieves this in the generator panel in the transistorised panel or the distribution box for the vibrating contact regulator.

Most faults that I have investigated are related to the connectors & the wires connections with the pins, crushing of the cable or defective earthing around the generator panel or distribution box.

When not running are there any connections to 24-12v regulators, phone chargers etc as these will drain volts away? Check that both batteries read the same voltage & one battery is not going down on you. I charge both 12v batteries independently to cater for there individual needs (which should be the same) rather than 24v across both. These batteries are of identical type & age?

All fit for form and function now, it was a problem with the shunt box all good now.