charger problems G04 power wise.

[Fire dragon]

I have by passed the relay and the charger will work and charge batteries. I installed a new timer/relay board and rewired correctly as I have changed boards previously. The charger will not work. Jumper across the two relay wires and it charges. took another old board and desoldered relay and resoldered in a new one, installed the board charger don't work. the number off of the new replacement board is 9012. This charger only had one board in it. I believe this is the wrong replacement board but cannot find any thing out about another board for this charger. Power wise 28115 G04.. I opened up two other G04 chargers and one had two boards and one had one. #8992010

any help would be appreciated..

[JohnnieB]

Here are the manuals for the charger and the single board retro-fit (which gives part# for the correct board as PN 28667-G01.)

You might have some bad boards, but it sounds like the cart's battery pack isn't being sensed, or the pack voltage is too low to turn on charger.

There are two wires attached to the control board that connects the cart's battery pack to it. One connects to the heatsink in the charger and the other connects to the third wire in the output cable.

Whenever the charger is connected to cart, full battery pack voltage should be present between those two wires where they connect to the control board.

Without being plugged into AC power, the relay in the charger should click when charger plug is plugged into cart. Otherwise the the control board is not sensing battery pack voltage (has to be above about 28V for a 36V charger), or control board is bad.

[Fire dragon]

The battery pack was at 39 volts. I thought the red wire from the board to the charger cord to cart was a safety so you could not operate the cart while plugged in. Not sure what that would have to do with the charger starting?? But will check the voltage at the points indicated. Thanks.

[JohnnieB]

Originally Posted by Fire dragon

The battery pack was at 39 volts. I thought the red wire from the board to the charger cord to cart was a safety so you could not operate the cart while plugged in. Not sure what that would have to do with the charger starting?? But will check the voltage at the points indicated. Thanks.

Two separate, independent circuits. One is on the + side and the other is on the - side.

The small wire coming out of the cart's charger receptacle is what disables the cart when the charger's plug in inserted. (Reed switch in the receptacle opens when the magnet in the charge plug gets near it and removes the positive voltage source from the KSI circuit)

The third wire in the charger's output cable senses the battery pack voltage.
The auxiliary contact in the charger plug (Item # 36 in attached drawing) touches the outside of the Negative terminal (Radsok) in the receptacle to sense the pack voltage.

How it works is that the cart's battery pack voltage energizes the relay inside the charger, turning the charger on.
If you plug the charger into the cart before you plug charger ihto AC outlet, you should hear the relay inside the charger click.

If you have 39V at the battery pack, you should have 39V at the control board.

[Fire dragon]

That makes it a lot clearer. Thanks. A person can really learn a lot if the just read this forum. Appreciate the help and info.. Will check the voltage today and see what I find. Thanks again.

[Fire dragon]

took apart the plug end of cord and the red wire was disconnected. Charger is now working thank you very much. Hope I can remember that for the future..

[JohnnieB]

Glad you found the problem and fixed it.

Thanks for the feedback.

[jdufoe]

Having same issues - replaced board and wired in heat sink line through DC plug. If I jump relay on board, I get voltage at charger plug. Also checked plug wires and all looks good.

[JohnnieB]

Originally Posted by jdufoe

Having same issues - replaced board and wired in heat sink line through DC plug. If I jump relay on board, I get voltage at charger plug. Also checked plug wires and all looks good.

There are two battery sense wires attached to the control board.
The red one attaches to the heat sink, which in turn connects to the B+ terminal on the battery pack via the positive radsok in the output plug.
The black one connects to the B- terminal on the battery pack via the third wire in the output cable and the Auxiliary contact in the output plug touching the outside of the negative radsok in the cart's charger receptacle.