Water seals around the headlight assemblies fail consistently, allowing moisture to pool inside the housings. This causes headlights to go dark, turn signals to fail, and fuses to blow repeatedly—sometimes even after replacement bulbs are installed. Multiple owners report this problem recurring even after spending $1,600–$1,800 to replace one headlight assembly. GM issued a recall for a similar issue on the Cadillac SRX (2010–2015), but Regal owners say dealerships refuse to cover the same defect on their vehicles.
Complete electrical power loss while driving is reported by at least two owners. The vehicle shuts down entirely—no lights, no emergency flashers, no power steering or brakes—creating an immediate crash risk. Battery and alternator diagnostics come back normal, yet the problem recurs. One owner had the alternator replaced two weeks after the initial failure, with no resolution.
Battery drain is a recurring complaint: batteries die overnight or fail to hold charge despite multiple replacements. Mechanics confirm the battery and alternator test good, pointing to a deeper voltage drain issue that remains undiagnosed. Random electrical shorts plague power windows, radios, interior lights, and seat adjusters—some work, some don't, with no clear pattern or permanent fix documented. One owner reports a diagnostic code P0062 (Electrical Control Module) but no follow-up on what was done about it.
Failure modes owners describe
Headlight assembly water intrusion and condensation
Water seals around headlight assemblies fail, allowing standing water and condensation to accumulate inside the lamp housings. This causes bulb failure, blown fuses, and complete loss of headlight function. Multiple owners report the same issue recurring even after replacement. Some note ballast/HID component failure secondary to moisture exposure.
When: Reported across various mileages (34K to 66K+); occurs early in ownership and recurs
Symptoms owners cite: Standing water visible in headlight assembly; Condensation inside headlight lens; Headlight goes dark or fails entirely; Left turn signal failure; Driver-side brake light failure; Fuses blown repeatedly when attempting repair
Codes mentioned: Blown headlight/turn signal fuses
Repairs/costs cited: Headlight assembly replacement cited at $1,600–$1,800 per side; ballast replacement mentioned. One owner reported $3,200–$5,000 total repair estimate from dealership.
Recalls/TSBs owners mention: GM and Cadillac addressed similar issue on Cadillac SRX (2010–2015) with recall; Buick Regal owners report dealership refusal to cover repair and no recall issued for this model.
Complete electrical power loss while driving
Vehicle experiences sudden total loss of electrical power while in motion, resulting in engine stall, loss of brake lights, loss of emergency flashers, loss of power steering and brakes. Battery and alternator diagnostics are inconclusive; issue recurs intermittently. One owner reports the problem occurred twice before alternator replacement.
When: Occurred while vehicle moving at highway speed; intermittent and recurring
Symptoms owners cite: Complete electrical shutdown while driving; Engine stalls mid-motion; No electrical systems respond (lights, 4-way flashers, power steering, brakes); Battery drains despite recent charging; Battery shows no dead cells but is nearly drained; Vehicle restarts after shutdown
Codes mentioned: P0062 (Electrical Control Module, GCM)
Repairs/costs cited: Alternator replaced 2 weeks after initial power loss diagnosis; battery subsequently replaced. Issue persisted or recurred post-repair in some cases.
Battery discharge and voltage drain
Battery loses charge overnight, completely drains, or fails to hold charge despite repeated replacements. Owner reports battery, alternator, and starter tested good by mechanic. One owner had alternator and battery replaced; another owner diagnosed with voltage drainage issue by independent mechanic after failure to restart.
When: Occurs randomly and repeatedly; one report at 66K miles
Symptoms owners cite: Battery completely dead overnight; Battery dies after holding charge for only a couple of days; Battery drains despite being recently charged; Vehicle will not start without external boost or recharge; Battery and alternator test good but drain continues
Codes mentioned: Voltage drainage issue (diagnosed by independent mechanic)
Repairs/costs cited: Battery replaced multiple times without resolution; alternator replaced in one case; starter verified good.
Intermittent electrical shorts and component failures
Random electrical gremlins affecting multiple systems: power window controls work intermittently, radio turns on/off spontaneously, interior lights activate/deactivate without user input, driver seat power adjuster malfunctions, digital speedometer stops working temporarily. Pattern suggests internal short or loose connection rather than component failure.
When: Occurs randomly and intermittently; reported at 58K miles for interior lighting/radio
Symptoms owners cite: Power window buttons work some days, not others; Radio spontaneously turns on and off; Interior lighting turns on/off without warning; Digital speedometer stops working, then restarts; Power seat adjuster requires multiple attempts to function
Repairs/costs cited: No repairs documented for these individual issues; one owner reports dealer unable to diagnose or repair interior lighting/radio problem.
Headlight ballast failure and blown fuses
Headlight ballast (HID component) fails, preventing headlights from powering on. Fuse replacement alone does not resolve the issue; entire headlight assembly must be replaced. Failures occur even with new bulbs installed.
When: Reported at 35K+ miles
Symptoms owners cite: Headlights do not illuminate despite bulb replacement; Fuses blown repeatedly; Headlamp assembly not receiving power
Codes mentioned: Blown headlight fuses
Repairs/costs cited: Headlamp assembly replacement at $1,600 each; ballast replacement mentioned as root cause.
Condensation and blown fuse in headlight circuit
Condensation accumulates in headlight assembly and triggers blown fuse in the headlight circuit. No diagnostic codes are stored, making the issue difficult for dealer to identify without direct inspection.
When: Reported at 34K miles
Symptoms owners cite: Condensation visible in driver-side headlight; Fuse blown in headlight circuit; No warning lights illuminated
Repairs/costs cited: Vehicle not repaired; owner did not pursue dealer or manufacturer contact.
Synthesized from 14 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.