'95 Electric 48v PowerDrive won't Charge

[shadowman]

they grey wire is the OBC wire......as many places down there you should be able to find someone with a decent price.......try some of our site sponsers they are as good as the rest out there...........................

[schesley]

I haven't replaced the OBC yet. I read on another site about bypassing the relay on the charger to take the OBC out of the picture. Has anyone tried this? If I do this and it charges, it would seem like it has to be the OBC. Can someone talk me through the process?

[DieselDave]

I am new at this golf cart stuff but I am having similar problems as you. There are great manuals on this site you can download that explain the charging system and the chargers. The gray wire you are asking about is called the sense wire. The cart (obc) sends 48v through the gray wire to the charger to turn the charger on. The 48v that is sent to the charger via the gray wire closes a relay that allows the 120v ac to reach the primary of the transformer. There are items that go bad in the charger that can cause a low charge output and you can isolate the problem if you are able to troubleshoot basic electrical items. Also there are great sites on eBay that sell items to rebuild your charger if need be for just a few dollars. I would use the pdf downloads on this site to make sure your charger is working correctly and that your cart is wired correctly before you start throwing parts at it. If you are not able to understand the schematics and trouble shooting guides that are offered on this site then perhaps the best bet for you is to throw parts at it in the order that fail the most frequently. It appears that many on this site have been successful by replacing their obc's.

[DieselDave]

schesley, as to your question regarding bypassing the relay to take the obc out of the equation, this is quite easy to do. The instructions are in the sticky download for your battery charger. The bypassing of the relay was meant to be used as a trouble shooting aid only and not to make the charger operational. If you run your charger with the relay bypassed you are going to over charge and sometimes undercharge your batteries, this will be very expensive in the long run as you run a good chance of ruining your batteries and even causing a fire. The obc is what controls the charger to give the optimum charge for the different conditions.

[schesley]

DeiselDave,

Bypassing the relay is only meant as an additional check to try to isolate the real problem. It probably is the OCB, but I don't want to just throw parts at it without being sure. I was looking at a schematic yesterday. It is not in front of me now. I think I can jump the normally open on the relay, I think it was a brown wire, and an orange wire. If the cart charges then, I will be fairly certain it is the OCB.

Thanks

[shadowman]

there is nothing else there other than the OBC to keep the cart from charging.............................

[schesley]

Thanks, Shadowman. You've been a lot of help. I guess I'm just suffering a little sticker shock at seeing how much an OBC costs. I'm just going to have to bite the bullet.

[DieselDave]

My bad, I stated in post 14 above that the obc closes the charge relay inside the charger by supplying 48v to the relay. The gray wire closes the charge relay by supplying ground to the charge relay and not power. Sorry.

[shadowman]

the only other way around it is to buy an aftermarket charger that allows you to eliminate the OBC...............however it cost 2 or 3 times what an OBC cost..............................

[schesley]

You'll never guess what ended up being wrong. It was the OBC. Charging properly now. One small issue. The reverse buzzer is not working. I noticed a small (approx 18ga) red w/white stripe wire after I disconnected the two black wires. It may have been attached at the top of the B- so it was not noticible when I took things apart. The lug was the right size, so I hooked it to B- along with the two black wires. Does this sound right? As you have read in previous posts, the buzzer never sounded when I had tried to reset the OBC. It had always worked in reverse until I changed the OBC. Any thougts?