B1630 – Right low beam control circuit high (Dodge)

B1630 means your 2007 Dodge Charger has a fault in the right low-beam headlamp control circuit, and the headlight may not work correctly. You will usually notice a right low beam that stays off, stays on, or acts intermittent. According to Dodge factory diagnostic data, this code indicates a “Right low beam control circuit high.” This is a Dodge manufacturer-specific body code, so the exact monitoring strategy can vary by platform. Treat it as a direction to test the right low-beam control circuit and its connectors under load, not as proof that the bulb or module has failed.

B1630 Quick Answer

This code sets when the Dodge body/lighting controller sees the right low-beam control circuit stuck “high” when it should not be. Start by verifying right low-beam operation, then test the control wire, connector condition, and grounds before replacing parts.

What Does B1630 Mean?

Official definition: “Right low beam control circuit high.” In plain terms, the module that controls or supervises exterior lighting thinks the right low-beam control line has higher-than-expected electrical state, so it cannot command the lamp normally. In practice, that can make the right low beam inoperative, stuck on, or unreliable, depending on how your Charger’s lighting is configured.

What the module is checking: The controller monitors the right low-beam control circuit for plausibility while it commands the lamp on and off. A “circuit high” fault means the module sees that control line remain at a high electrical level when the module expects it to be low, or it sees a high state that does not match the command. Why that matters: This points you to wiring integrity, connector condition, and driver control logic first. It does not, by itself, confirm a bad bulb, a bad headlamp unit, or a failed module.

Theory of Operation

On Dodge vehicles, the body system manages exterior lighting using a control module and dedicated circuits. The module commands the right low beam based on the headlamp switch input and, on some trims, other logic like automatic headlamps. The circuit then delivers power or control to the right low-beam load through wiring, connectors, and grounds.

B1630 sets when the controller cannot pull the right low-beam control circuit to the expected state. A short to voltage, a backfeed through damaged wiring, or a poor ground that changes circuit behavior can hold the line high. An incorrect bulb type, an aftermarket headlamp harness, or corrosion in the right-front connectors can also distort the circuit enough to trigger the “high” condition.

Symptoms

These are the most common signs drivers and technicians see with B1630 on Dodge lighting systems.

• Right low beam out even though the left low beam works normally
• Right low beam stuck on or stays on after you switch headlights off
• Intermittent lighting that changes with bumps, rain, or turning the wheel
• Flicker of the right low beam, especially at idle or with loads on
• Cluster message or lamp-out indicator behavior (varies by Charger equipment)
• Stored body DTCs related to exterior lighting outputs or headlamp requests
• Heat or odor near the right headlamp connector from high resistance or arcing

Common Causes

• Short to voltage on the right low beam control wire: Contact with a B+ feed backfeeds the control circuit and keeps the sense voltage high.
• Open control circuit or high resistance in the control wire: A broken conductor or spread terminal prevents the module from pulling the circuit to the commanded state, so the feedback stays high.
• Corroded or water-intruded headlamp connector: Corrosion increases resistance and can bridge terminals, which skews the module’s circuit-high monitoring.
• Damaged harness near the right headlamp assembly: Rub-through at the radiator support or behind the lamp lets the control wire chafe into a power feed or lose continuity.
• Incorrect bulb type or incorrect lamp assembly wiring: An aftermarket lamp or wrong bulb can change current flow and confuse the module’s output feedback logic.
• Stuck relay or integrated driver not releasing (platform dependent): Some Dodge lighting architectures use relays or solid-state drivers, and a stuck-on path can hold voltage high on the control side.
• Poor module ground or power feed integrity: A weak ground or voltage drop on the module supply can distort the output stage and its diagnostic sense circuit.
• Previous repair issues (pin fit, backprobing damage, wrong splice): Loose terminal tension or an incorrect splice can create intermittent opens that set a circuit-high DTC on key-on tests.

Diagnosis Steps

You need a scan tool with body/Dodge lighting data, a digital multimeter, and a test light. Use backprobing pins and a wiring diagram for the right low beam control circuit. A fused jumper wire helps for controlled load tests. Plan to perform voltage-drop tests with the circuit operating, not continuity checks alone.

1. Confirm B1630 in the scan tool and record stored vs pending status. Save freeze frame data if the module provides it. For this circuit-high code, focus on battery voltage, ignition state, headlamp switch state, and any listed lamp command or feedback PIDs. Freeze frame shows the exact conditions when the fault set. Use a manual scan-tool snapshot later to catch an intermittent fault during a wiggle test.
2. Check the obvious power distribution first. Inspect related fuses, fuse box signs of heat, and the right headlamp area for harness damage. Do this before any meter work at the module. A quick visual often finds a rubbed-through section near the radiator support or headlamp pocket.
3. Verify module power and ground integrity under load. Keep the right low beam commanded ON and measure voltage drop from module ground to battery negative. Target less than 0.1 V drop with the circuit operating. Next, check voltage drop on the module’s power feed from battery positive to the module B+ pin while loaded. A weak feed or ground can create false output diagnostics.
4. Run a full scan and note related lighting or body codes. Look for codes that point to headlamp switch inputs, front control modules, or lamp output stages. Address shared power, ground, or network issues first when multiple lighting outputs show faults together.
5. Use bi-directional controls to command the right low beam ON and OFF. Watch any available “right low beam command” and “right low beam feedback/sense” PIDs. A circuit-high fault often shows feedback staying high when the module commands OFF. If the code returns immediately at key-on, treat it as a hard fault from the Comprehensive Component Monitor.
6. Inspect the right headlamp connector and terminals closely. Look for green corrosion, overheated plastic, terminal push-outs, and moisture trails. Perform a pin tension check with the correct mating terminal or test probe. Do not rely on a quick glance, since Dodge headlamp connectors can look clean and still have poor pin fit.
7. Isolate the lamp side from the control circuit. Disconnect the right headlamp connector and recheck the feedback PID or the DTC behavior while commanding the output. If the feedback drops to normal with the lamp unplugged, suspect the lamp assembly, bulb, or connector cross-feed. If the feedback still reads high, focus on the harness and module output circuit.
8. Check for a short to voltage on the control circuit with the lamp disconnected. With ignition ON and the output commanded OFF, measure voltage on the control wire at the headlamp connector. A high reading points to a short to B+ or backfeed from another circuit. Pull and reinstall nearby fuses one at a time if needed to identify which branch feeds the backfeed.
9. Load-test the control circuit for an open or high resistance. Command the right low beam ON and use a test light or appropriate load tool between the control wire and a known good ground at the headlamp connector. Then measure voltage drop along the control wire from the module connector to the headlamp connector while the load operates. A large drop indicates high resistance in the wire, splice, or terminal.
10. Perform a wiggle test with a scan-tool snapshot running. Wiggle the harness at the right headlamp pocket, radiator support, and any recent repair splices. A snapshot captures the moment the feedback changes during the disturbance. Compare that to the freeze frame, which captured the original setting conditions.
11. Verify the repair with a full functional check. Clear codes, cycle the ignition, and command the right low beam ON and OFF several times. Confirm the feedback PID follows the command and the DTC does not reset immediately. If the monitor behaves like a two-trip logic on your platform, complete two drive cycles and recheck for pending and stored status.

Professional tip: Do not condemn the lamp driver because the bulb works. A short-to-voltage can still let the lamp illuminate while forcing the control sense high when the module expects low. Always unplug the right headlamp first and see if the “high” condition disappears. That one split test saves hours and prevents needless module replacement.

Possible Fixes

• Repair short-to-voltage damage in the right low beam control harness: Restore insulation and routing, then secure the harness away from sharp edges and hot surfaces.
• Clean and repair the right headlamp connector: Remove corrosion, correct terminal tension, and replace terminals or the connector body when heat or water damage exists.
• Correct an open or high-resistance control circuit: Repair broken conductors, poor splices, or backed-out terminals verified by voltage-drop testing under load.
• Replace an incorrect bulb or incompatible lamp assembly: Install the correct right low beam bulb and verify the connector pinout matches the Dodge application.
• Restore module power/ground integrity: Repair power feed issues or ground path corrosion that fails voltage-drop limits with the circuit operating.
• Replace the lighting driver/module only after circuit proof: Replace the controlling module or driver stage only after you prove proper wiring integrity and confirm a failed output control response.

Can I Still Drive With B1630?

You can usually drive a 2007 Dodge Charger with B1630, but you should treat it as a lighting safety issue. This code points to the right low beam control circuit reading “high,” so the right low beam may not work as commanded or may behave unpredictably. Daytime driving may feel normal. Night driving becomes risky fast, especially on unlit roads or in rain. If the right low beam stays off, limit driving after dark and in poor weather. If the lamp stays on when it should not, you can drain the battery during parking. Confirm headlamp operation before you leave.

How Serious Is This Code?

B1630 ranges from an inconvenience to a real safety concern. If the right low beam still works and the issue happens intermittently, you may only notice a warning or occasional flicker. If the right low beam fails, you lose forward lighting coverage and side visibility. That raises crash risk at night and can trigger a traffic stop. Drivability does not change because this is a Body code, not an engine fault. Still, treat it as time-sensitive. A “circuit high” often points to an open control wire, a poor ground under load, or a short to voltage. Those faults can spread heat at connectors and create repeat failures.

Common Misdiagnoses

Technicians often replace the right headlamp bulb first because it seems obvious. A bulb rarely causes a “control circuit high” by itself on Dodge platforms. Another common miss is swapping the TIPM or headlamp module before checking the right low beam control wire for an open, a spread terminal, or corrosion. Many shops also check voltage with the connector unplugged. That test can look perfect and still fail under load. Skipping voltage-drop tests across grounds creates more wrong calls. Finally, some diagnose the wrong side. Verify the “right” lamp and confirm the code resets with the right low beam command.

Most Likely Fix

The most frequent confirmed repair direction involves wiring and connection integrity at the right headlamp connector and the underhood power distribution area. Start by verifying the right low beam command and measuring the control circuit under load. Many “circuit high” cases trace to an open in the control lead, a backed-out terminal, or corrosion that lifts the circuit voltage. A second common direction involves repairing a poor ground path at the lamp assembly or body ground point. Only consider a TIPM or driver fault after you prove the circuit and load operate correctly end-to-end.

Repair Costs

Repair cost depends on whether the confirmed root cause is a sensor, wiring, connector issue, or control module problem. Verify the fault electrically before replacing parts.

Last updated: March 31, 2026