Infiniti G35 / G37 Alternator: Replacement Guide, Costs & Upgrade Options
The Infiniti G35 and G37 occupy a unique position in the car audio world — premium Japanese rear-wheel-drive sports sedans and coupes with devoted followings in the audio and performance community. The VQ35DE and VQ37VHR engines are smooth, powerful, and popular platforms. But the stock alternator? It wasn’t built for serious electrical loads. Here’s the full guide.
Infiniti G35 / G37 Alternator Specs by Year and Engine
| Model | Years | Engine | Stock Output | JS Alternators |
|---|---|---|---|---|
| G35 Sedan/Coupe | 2003–2007 | 3.5L VQ35DE V6 | 120–130A | 250A |
| G35 Sedan | 2007–2008 | 3.5L VQ35HR V6 | 130A | 250A |
| G37 Sedan/Coupe | 2008–2013 | 3.7L VQ37VHR V6 | 130–150A | 250–320A |
| G37 IPL | 2011–2013 | 3.7L VQ37VHR V6 | 130–150A | 250–320A |
G35 / G37 as a Car Audio Platform
The G-body platform — shared with the Nissan 350Z (G35) and 370Z (G37) — is a favorite for enthusiast audio builds. The combination of rear-wheel drive, sports seating, and a premium cabin makes for a compelling audio platform. The large trunk on the sedan accommodates serious subwoofer and amplifier setups. However, the 120–150A stock alternator was designed for factory loads only.
A typical G37 factory electrical load runs 90–110A (headlights, climate, infotainment, ECU). A 500W audio system adds 50A — that’s 140–160A on a 130–150A alternator. At the limit before anything plays at full volume.
Common G35 / G37 Alternator Problems
- Headlights dimming on bass hits: Classic voltage sag. Stock alternator can’t supply audio demand plus factory load simultaneously.
- Alternator whine in audio: Big 3 wiring upgrade resolves this on G35/G37 builds.
- Early alternator failure on audio setups: Chronic overload. High output alternator solves the root cause.
- Battery not recovering overnight: Alternator underperforming or accessories drawing parasitic load.
Nissan 350Z / 370Z Note
The G35 shares its VQ35DE engine platform with the Nissan 350Z. The G37 shares the VQ37VHR with the Nissan 370Z. However, alternator fitment is not always identical between the Infiniti and Nissan applications due to differences in engine bay layout and mounting. Always verify by specific vehicle when ordering.
Infiniti G35 / G37 Alternator Replacement Cost
| Option | Parts | Shop Total |
|---|---|---|
| OEM Infiniti/Nissan | $160–$310 | $250–$480 |
| Remanufactured | $95–$180 | $185–$350 |
| JS Alternators 250A+ | $260–$390 | $350–$560 |
Installation Requirements
- Big 3 wiring upgrade: Complete Guide
- Shorter serpentine belt: spec included with your order
- ANL fuse on B+ wire: Fuse Sizing Guide
Related: Car Audio Alternator Upgrade Guide | Alternator Sizing Guide | Big 3 Wiring Upgrade Guide