Voltage reducer problem

Smokey046

Attempting to install a 48v reducer in my Club Car DS. My reducer has a positive and negative input, positive and negative output and a “key” wire. The input + wire has a 15 amp fuse in line.

I installed the input + to the first battery in series. I connected the output + to the fuse block positive stud. I connected the output - to the fuse block negative stud. I connected the key wire to the key switch. Now, when I connect the input - to either the last battery negative stud or the B1 stud on controller, there is a huge spark and it blows the in line input + fuse every time.

I attached a CRUDE quick illustration of the wiring setup. I have tested all connections with meter to no luck. I did have a couple of switch’s off of the fuse block (driving lights and light bar) grounded to the frame up front. I read a few moments ago that is ill advised. Surely that isn’t causing the short?

I am thinking faulty reducer? Any advice is appreciated!

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Hunter450

Check to see if the frame has any voltage reading. Also, your post mentioned the input wire being connected to the B terminal on the controller but your diagrams shows B- terminal which is correct. Are the switches grounded to the cart or are the devices the switches control grounded to the cart?

Smokey046

The input - is connected to the B- on controller. Two rocker switches are grounded to the frame, not the lights.

I checked frame voltage (after disconnecting fuse block) and found a voltage of 48.3v. I checked with positive terminal connected and negative disconnected and vice verse. Also with both connected and got the reading all three times. Actually higher with only positive terminal connected. I took the readings by using the negative battery terminal on last battery and touching frame.

So, it appears I have a problem. Batteries are brand new Trojans 8v. Installed a month ago or so. Frame and motor have dried mud on them except where I cleaned it to drain differential fluid etc. Cart is new to me and just acquired.

What next?! I have cleaned all electrical connections with wire brush and electrical contact cleaner spray, with the exception of the motor. New solenoid will be here tomorrow. Old one works but looks rough so it’s preventative.

Mooncarter

Don't ground anything to the frame. Undo it, and all negs. should run back to (one way or another) to pack neg.

Hunter450

Ok, you have pack voltage to the frame so first (BE SAFE!). Set the Tow/Run switch to Tow, disconnect the pack positive and negative cables. Check voltage to frame. If zero, start looking for anything that could be wired to or openly touching the frame. Good idea, to pull the dash and check the key switch wiring, reverse buzzer wiring is clear of the frame. Also, if there are misc. wires connected to the pack, follow that wiring and see where it goes. It's a process of elimination.

Smokey046

Ok, will do exactly that. My first question is do the 1997 Club Car DS have a tow switch? I cannot locate it anywhere and currently I have the body panels off down to the frame. Aside from that I will start examining it from front to back. So the frame voltage would make the reducer input fuse blow?

Appreciate the help very much!

_ogre

i'll be honest, i've never hooked one up, i'm surprised one of the wiring gurus here haven't said anything.
first you have to isolate your frame, as stated by 2 folks above, shouldn't be any voltage on the frame.

on to your connections...
you have 5 wires to hook up
positive and negative input go straight to the batteries for 48 volts
positive and negative output go to your fuse box
“key” wire connects to the key switch to turn the reducer on/off

your connections will be similar to this one from carts unlimited, scotty is a vendor here
his shows 4 wires, your reducer has 5. the extra is 12v- from fuse block
all 12v circuits need to have 12v+ and 12v- from the fuse block
no common grounding to the body like a automotive wiring

Mooncarter

What ogre said.

I think some 97 DS had a run/tow. Either yours does or it does not.

I never understood the drawing above, I'm sure it works but it looks to me like there is only 36 or 48 volt negative.


You have 2 inputs 48v, 2 outputs 12v. You also have "trigger" wire to "start" the reducer when key is switched on. Some say to hook 48v negative input to reducer not from pack negative but from B- at the controller so the OBC can monitor what the reducer is doing and charge the pack accordingly.

Smokey046

Great advice, thank you all. I will be working on the cart tomorrow and hopefully can track down the problem. I will let you know how it works out.

yawood

Sorry, I haven't answered this because I have been busy elsewhere and thought that this might take some time. NoleFan4Ever would have been a good source of information but he is on holiday and out of communication for a while.

Adding to what _Ogre said:

My approach to the reducer problem would be to test it in isolation from the frame and this should be comparatively easy if you already have the body off. So, remove it from the frame and disconnect all the cables.

1. Connect the 48V negative to the pack negative (last battery) - it WILL NOT be left there but this is just for testing the reducer (its permanent place is connected to B-).
   
2. Connect the 48V positive to the pack positive (first battery).
   
3. When you touch the positive to the terminal you will normally get a spark as the reducer's internal capacitors charge but this should not be big enough to blow the 15A fuse and it can be reduced by touching that cable to an old incandescent globe then touch the globe to the terminal (the resistance charges the capacitors more slowly).

If you still get a huge spark and the fuse blows then it probably indicates that there is an internal short of some kind and the reducer needs to be repaired or replaced.

If it connects OK and the fuse does not blow then connect the trigger wire to the 48V positive and test the output voltage to see if it is 12V. If that is OK then the reducer is fine.

With the cables still connected place the reducer back on the frame. If the fuse immediately blows then there is another issue. This may be an internal short in the reducer to the reducer case or something to do with a voltage from the frame.

Either way I would be checking the other wiring anyway to make sure that nothing is deliberately earthed to the frame. All negatives should go back to their power source via a dedicated negative cable. For example all 12V accessories should have their positives coming from your 12V distribution point and their negatives to the negative of your distribution point via dedicated wires.

If it turns out that you have an issue with the carts electrical system (as opposed to the reducer and accessories) then I'm not the person to help and maybe others will chime in.

Good luck.