How to Extend a Vehicle GPS Antenna Cable (Fakra Guide)

Swapping your head unit for an aftermarket unit, relocating a GPS antenna to a better position, or retrofitting a telematics module in a vehicle that didn't come with one — all of these jobs eventually hit the same obstacle: the OEM GPS antenna cable is too short, and it ends in a connector you've probably never seen before. That connector is called Fakra, and once you understand the system, ordering the right extension cable is straightforward.

What Fakra Is

Fakra is a standardized automotive RF connector system defined by DIN 72594-1. It was designed specifically for in-vehicle use: it's a push-and-click connector with a locking tab, built to survive temperature cycling, vibration, and the tight routing constraints of modern dashboards. Fakra connectors are color-coded by application, which means the color tells you what the cable is used for — not just what frequency it carries.

The connectors are keyed so that a Fakra plug for GPS (black) physically won't fully click into a Fakra socket for diversity antenna (blue) even though they look nearly identical. This keying prevents mislabeled connections during manufacturing. Each color corresponds to a standardized impedance code in DIN 72594-1, and virtually all are 50 ohms for RF signal applications.

Fakra Color Chart

For GPS extension work you need Fakra Z (black). Ordering any other color will result in a connector that either won't physically mate or will connect to the wrong system in the vehicle's wiring harness.

Active vs Passive GPS Antennas: Critical Distinction

This is the most important thing to understand before ordering any GPS antenna extension cable. GPS antennas come in two types:

Passive antennas are simple receive elements with no electronics. They pass the raw signal from the antenna element directly to the head unit or GPS receiver. They require no power and can be extended with any standard coax cable.

Active antennas contain a built-in low-noise amplifier (LNA) that amplifies the GPS signal (1575.42 MHz) before it travels down the coax. This matters because GPS signals are extremely weak — about -130 dBm at the antenna. An active antenna adds 20–30 dB of gain, which overcomes the cable loss and noise figure of the downstream electronics. Active antennas need 3–5V DC power, and this power is supplied by the head unit through the center conductor of the coaxial cable — a technique called phantom power or DC bias.

The critical consequence: if you insert a passive coupler or splitter between an active antenna and the head unit, you interrupt the DC power path and the LNA shuts off. You'll see no GPS lock or extremely poor acquisition. Any extension cable for an active GPS antenna must pass the DC bias straight through — a simple coaxial cable does this by definition, so standard extension cables are fine. What you must avoid is any passive combiner or splitter in the path.

Most European vehicles (BMW, VW, Audi, Mercedes) use active GPS antennas. Check your service documentation or measure DC voltage on the GPS antenna port to confirm: if you read 3–5V between center pin and shield, it's active.

Vehicle Manufacturer Reference

Male-to-Male Fakra Z Extension (Most Common Need)

The most common GPS extension scenario: the OEM antenna has a Fakra Z male plug, and the head unit has a Fakra Z female socket. You need a male-to-male extension cable that adds length between them. RG316 is the preferred cable for this application — it's only 2.5mm in diameter, handles the tight routing paths inside a dashboard, and has adequate loss for GPS frequencies (1575 MHz). RG58 is 5mm and stiffer, but works if RG316 isn't available or you need a slightly more durable cable for an under-dash installation.

RG316 Fakra Z Male to Fakra Z Male  |  RG58 Fakra Z Male to Fakra Z Male

Female-to-Female Coupler Applications

Some installations use a Fakra Z female-to-female coupler cable to join two existing cable runs — for example, when the OEM harness has a female socket exposed in the dash and you're connecting to an aftermarket antenna that also has a female socket. This is less common but does occur in telematics retrofit work.

RG58 Fakra Z Female to Fakra Z Female

Fakra Z to SMA: Aftermarket Head Units

Many aftermarket Android head units, especially universal double-DIN units, use an SMA female port for the external GPS antenna rather than a Fakra connector. If your vehicle's OEM GPS antenna ends in Fakra Z male and your new head unit has an SMA female port, you need a Fakra Z to SMA adapter cable:

RG316 Fakra Z Female to SMA Male

Fakra Z to MCX: GPS Receiver Modules

Standalone GPS receiver modules (u-blox, SiRF) commonly use MCX connectors — a small snap-on connector about 3mm in diameter. If you're connecting the vehicle's Fakra Z OEM harness to an aftermarket GPS module, you need a Fakra Z to MCX cable:

RG316 Fakra Z Male to MCX Male

Why RG316 Is Preferred for In-Dash Work

RG316 has a 2.5mm outer diameter, an FEP (fluorinated ethylene propylene) jacket that handles the heat cycling inside a dashboard without cracking, and a loss of approximately 3.5 dB per 10 feet at 1575 MHz. For a typical extension run of 3–6 feet inside a vehicle, this represents under 2 dB of total loss — negligible for an active antenna with 20+ dB of gain. RG174 (3.5mm diameter) and RG58 (5mm) also work, but RG316's flexibility and small diameter make it far easier to route through dashboard grommets and firewall pass-throughs.

Common Mistakes

Wrong Fakra color. Ordering Fakra B (blue, diversity) instead of Fakra Z (black, GPS) is a frequent mistake because the connectors look almost identical in product photos. Always check the color code explicitly.

Forgetting active antenna power. Cutting the DC power path through a splitter or passive combiner will disable the LNA and result in poor or no GPS reception. If you must split the GPS signal, use an active GPS signal splitter that maintains the DC path to the antenna.

Ordering male when you need female. The OEM antenna plug coming out of the dashboard is usually male. The head unit socket is female. A male-to-male extension cable bridges the two. Sketch your connection before ordering: antenna plug (male) → extension cable male end → extension cable male end → head unit socket (female).