If you're converting a Club Car from lead-acid to lithium, the factory OBC (On-Board Computer) is one of the most common reasons a cart won't charge correctly—or won't drive after the install. The OBC was built around lead-acid charging behavior, and on many carts it also controls two critical functions:
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The negative charging path The OBC acts as a "gatekeeper"—the negative circuit for the charger runs through it. A lithium charger can't communicate with the lead-acid OBC, so charging may not work correctly at all.
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The charger interlock The OBC tells the controller the cart is plugged in and shouldn't move. Without the bypass, the cart may think it's perpetually "charging" and refuse to drive.
This guide answers common questions about a Club Car OBC bypass for lithium, then walks through the bypass steps for the Club Car DS (36V & 48V) and Club Car Precedent (2004–2013).
Safety First — Read Before Touching Wiring
⚠️ You're working around high-current wiring. If you're not comfortable identifying wires, making solid crimps and splices, and verifying connections, have a qualified golf cart technician perform the bypass.
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Put the cart in Tow modeOr fully shut down pack power on carts without a run/tow switch before starting any wiring work.
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Take photos before you cut or move anythingDocument the original wiring so you have a reference if something needs to be reversed or revisited.
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Use proper connectors and insulationHeat shrink is preferred over tape. All splices should be tight, fully insulated, and strain-relieved before the cart is powered up.
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Never leave cut wires exposedCap, heat-shrink, or tape every cut wire end—including the ones you're abandoning. Exposed wires in a battery tray are a short-circuit risk.
Prefer a visual walkthrough? Watch the OBC bypass video: How to Bypass OBC for Club Car DS by Bedrock Battery →
What "Bypassing the OBC" Actually Means
When people say "bypass the OBC," they're typically doing three things—and skipping any one of them can leave the cart broken in a different way:
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Disabling lead-acid-only sense wiring at the receptacleThe gray wire (and sometimes a small black wire) are OBC-specific signals that have no function on a lithium system. They need to be cut and capped off.
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Restoring a direct negative path for the lithium chargerThe OBC intercepts the negative charging circuit. With it bypassed, you create a clean direct path from the charger receptacle to the battery negative terminal.
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Restoring the interlock "Go" signalThe OBC tells the controller when it's safe to drive. Splicing the blue and white wires together completes this circuit, so the controller receives the "charger unplugged / Go" signal even with the OBC removed.
Do All Club Cars Need an OBC Bypass?
Quick Answer
Not always. Some Club Car DS 36V models do not have an OBC. If your cart doesn't have an OBC module or harness in the battery tray, you can skip the bypass steps entirely and proceed with the lithium install. For carts that do have an OBC—especially all Precedents and many DS models—bypassing it is commonly required for clean lithium charging and normal drive behavior.
Club Car DS (36V & 48V) — Step-by-Step
Club Car DS
36V & 48V
Note for 36V DS owners: Some 36V DS models do not have an OBC. If your cart has no OBC module or harness in the battery tray, skip this section entirely.
1
Cut the gray wire and small black wire at the charger receptacle At the charger receptacle, locate the thin gray wire. This is a lead-acid "sense" wire with no function on a lithium system. Cut it and heat-shrink or tape it off. Also locate the thin small black wire running from the receptacle to the OBC. Cut it and heat-shrink or tape it off.
2
Create a direct negative path for the charger (10-gauge black wire) On many DS carts, the OBC sits in the negative charging circuit as a gatekeeper. Locate the 10-gauge black wire attached to the charger receptacle (negative charging circuit). Connect this wire directly to the main negative terminal on your new lithium battery. ✓ Result: the lithium charger now has a clean, direct negative path to the battery.
3
Bypass the interlock — splice blue and white wires (6-pin connector) Locate the 6-pin plastic connector coming from the OBC. Unplug the OBC from the cart's main wire harness. On the OBC harness side (wires running toward the front of the cart), cut all six wires. Identify the blue wire and white wire on that harness side—these are consistent across both 36V and 48V OBC harnesses. Splice the blue and white wires together using a butt connector. Heat-shrink, tape, or cap the remaining four cut wires. Plug the 6-pin connector back together. ✓ Result: the controller receives the "charger disconnected / Go" signal and the cart will drive.
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Heavy black pass-through wire — only if replacing main battery cables with 2 AWG Only perform this step if you are upgrading the main battery cables. You may find a heavy 6-gauge black wire passing through the hole in the center of the OBC, running from the controller B− terminal to battery negative. Cut the terminal lug, pull the wire out of the OBC pass-through, and run a new 2 AWG cable from the controller B− directly to the main negative terminal of the lithium battery.
Club Car Precedent (2004–2013) — Step-by-Step
Club Car Precedent
2004–2013
1
Cut the gray wire and small black wire at the charger receptacle At the charger receptacle, locate the thin gray sense wire used only by the lead-acid OBC. Cut it and heat-shrink or tape it off. Also locate the small black wire from the receptacle to the OBC—unclip it at the connector if one exists, or cut it if there's no connector. Heat-shrink or tape it off.
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Create a direct negative path (10-gauge black wire through OBC hole) Many Precedents have a 10-gauge black wire that runs from the controller and feeds through the OBC hole before reaching the battery. Locate this wire and connect it directly to the main negative terminal on your new lithium battery, bypassing the OBC entirely. ✓ Result: direct negative path established for the lithium charger.
3
Bypass the interlock — 6-pin Deutsch connector (blue and white wires) On the Precedent, the OBC typically uses a triangular or rectangular 6-pin Deutsch connector. Locate the OBC—under the center plastic cover in the battery tray for 2004–2008 models, or on the rear aluminum plate in the tray for 2009–2013 models. Follow the harness to the 6-pin plug and unplug the OBC from the main wire harness. On the OBC harness side, cut all six wires. Identify the blue wire and white wire and splice them together using a butt connector. Heat-shrink, tape, or cap the remaining four cut wires. Plug the 6-pin connector back together. ✓ Result: the controller receives the "charger disconnected / Go" signal. The cart will drive.
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If the cart still won't power up — solenoid ground (yellow wire, i2/Excel only) Most Precedents are done after Step 3. If the cart still won't turn on after completing the conversion, this step may apply to your model. On some Precedent i2 (Excel) models, the OBC controls the ground for the solenoid. Locate the yellow wire on the small terminal of the solenoid and disconnect it. Run a new wire (16–14 AWG with 5/16" ring terminals) from that same solenoid terminal to the main negative of the battery pack. ✓ Result: the solenoid is grounded directly, bypassing the OBC's "permission" to start.
Post-Bypass Checks — Don't Skip These
After completing your bypass, verify each of the following before putting the cart back in Run mode:
- ✓All splices are tight, fully insulated with heat shrink, and strain-relieved
- ✓Charge receptacle wiring is secure, protected, and no bare wire is exposed
- ✓All capped/taped cut wires are fully insulated — nothing bare in the battery tray
- ✓6-pin connector is plugged back together and seated fully
- ✓Cart is put back in Run only after rechecking all connections
- ✓Charge to 100% and wait until the charger shuts off before the first drive
- ✓Test drive on flat ground first, then under normal load
For a full post-install validation checklist covering fitment, charging behavior, and first-week checks: Golf Cart Lithium Conversion Checklist →
Haven't Purchased a Kit Yet?
If you're researching the OBC bypass before buying lithium, you're doing it the right way. This is one of the most common hidden steps in Club Car conversions—and where installs go sideways when owners are left guessing on wiring and charging behavior. Reach out with your cart model/year (DS or Precedent), voltage (36V/48V), and whether your Precedent is i2/Excel. We'll confirm whether your cart needs an OBC bypass and which conversion path matches your setup.
Shop Bedrock Conversion Kits →Frequently Asked Questions
Do I always need to bypass the OBC for a lithium conversion?
On many Club Car DS and Precedent carts with an OBC, yes—because the OBC was built for lead-acid charging and can interrupt the negative charging path and interlock behavior. Some DS 36V carts don't have an OBC at all and can skip this section entirely.
What happens if I don't bypass the interlock?
The cart may think a charger is always connected and refuse to drive. Splicing the blue and white wires on the OBC harness side of the 6-pin connector completes the "Go" circuit so the controller allows the cart to move normally.
Why do I have to charge to 100% before driving?
That first full charge helps calibrate the BMS and balance the cells so state-of-charge behavior and performance remain consistent from the first drive onward. Don't skip it—start the first drive only after the charger has completed and shut off on its own.