FAQ
TL;DR: To power LED DRL on a Golf IV, use an ignition‑switched 12 V from the cabin fuse/relay box; “look for 12 V only on the key.” [Elektroda, Staszek49, post #16713152]
Why it matters:** This helps DIYers wire DRL safely so they work with ignition and avoid dim, unsafe installs.
- Ignition‑switched 12 V is available at the cabin fuse/relay box ahead of the driver’s left knee; verify with a test light. [Elektroda, Staszek49, post #16713152]
- Battery‑top mini 30 A fuses are +30 (constant battery), not ignition‑switched. [Elektroda, Strumien swiadomosci swia, post #16713096]
- You can pull a feed from the battery/fuse links if routing is easier. [Elektroda, moto-kord, post #16712869]
- Use DRL with proper approvals; non‑approved LEDs risk fines or rejection. [Elektroda, Pedros050, post #16712887]
- Weak grille strips reduce visibility; use low beam in heavy rain. [Elektroda, kwok, post #16712941]
Quick Facts
- Ignition‑switched 12 V is available at the cabin fuse/relay box ahead of the driver’s left knee; verify with a test light. [Elektroda, Staszek49, post #16713152]
- Battery‑top mini 30 A fuses are +30 (constant battery), not ignition‑switched. [Elektroda, Strumien swiadomosci swia, post #16713096]
- You can pull a feed from the battery/fuse links if routing is easier. [Elektroda, moto-kord, post #16712869]
- Use DRL with proper approvals; non‑approved LEDs risk fines or rejection. [Elektroda, Pedros050, post #16712887]
- Weak grille strips reduce visibility; use low beam in heavy rain. [Elektroda, kwok, post #16712941]
Where can I find an ignition‑switched 12 V in a Golf IV 1.6 SR?
Tap the cabin fuse/relay box in front of the driver’s left knee. Probe for a stud or thick wire that shows 12 V only with the key on. Use a test light or multimeter to confirm before connecting your DRL controller. “Look for 12 V only on the key.” [Elektroda, Staszek49, post #16713152]
Can I take the plus from the battery fuse box instead?
Yes. You can route power from the fuses on the battery if that path is cleaner for your install. Protect the new circuit with an inline fuse close to the source and verify whether it’s constant or ignition‑switched before relying on it. [Elektroda, moto-kord, post #16712869]
Which fuses on the battery are constant +30?
The small 30 A fuses on the battery are +30, meaning permanent battery power. They do not turn off with the ignition, so do not use them for DRL ignition sense unless your controller requires a constant feed. Use a separate ignition‑switched signal to control the relay. [Elektroda, Strumien swiadomosci swia, post #16713096]
How do I fish a wire through the firewall safely?
Use the existing bulkhead pass‑throughs near the cabin fuse/relay box. After confirming the correct stud, run your wire through the grommet and protect it with loom. Secure it away from pedals and sharp edges. Test voltage before finalizing the route. [Elektroda, Staszek49, post #16713152]
Is using the reverse‑gear switch a good ignition source on an automatic?
No. The reverse circuit only has power in reverse, and routing differs on automatic gearboxes. Your DRL would turn on only in reverse, which is unsafe. Use an ignition‑switched feed from the cabin box instead. [Elektroda, Eltronfun, post #16713043]
What approvals do my LED DRL need?
Use DRL units with proper markings and approvals. Without approvals, you risk being stopped or fined. Choose branded, certified DRL modules and mount them per guidance to ensure compliance and visibility. Keep proof of approval with your vehicle documents. [Elektroda, Pedros050, post #16712887]
Are grille‑mounted LED strips bright enough for daytime safety?
Often not. Users report many grille strips are barely visible, especially in rain. In poor weather, switch on low beams for full front and rear visibility. “It is better not to mount it… you have a low beam and it’s good.” [Elektroda, kwok, post #16712941]
What does “+30” mean here, and how is it different from an ignition feed?
+30 is constant battery power, such as the small 30 A battery‑top fuses. An ignition feed switches with the key and is found in the cabin fuse/relay box. Use +30 for constant supply and a separate ignition signal for control. [Elektroda, Strumien swiadomosci swia, post #16713096]
Any quick 3‑step method to find the right ignition wire?
- Remove the left‑knee fuse/relay cover and expose the studs/thick wires.
- With a test light, probe for 12 V only when the key is ON.
- Confirm again after cycling the key, then connect via a fused lead. [Elektroda, Staszek49, post #16713152]
Can I trigger DRL from the horn or alternator wiring?
You can inspect the horn or alternator cables to find a suitable switched signal. Verify with a meter that the chosen point is truly ignition‑controlled, not transient or load‑dependent. Use a relay to isolate the DRL circuit from vehicle systems. [Elektroda, DriverMSG, post #16712908]
Someone mentioned the ABS fuse—should I use it?
One suggestion was to attach at the battery‑top fuse box, referencing the ABS area. If you consider that route, ensure you do not compromise the ABS circuit. Take power via an add‑on fused lead, not by piggybacking critical safety fuses. [Elektroda, moto-kord, post #16713091]
What tool should I use to test for the correct wire?
Use a bulb‑type test light or a digital multimeter. Verify the candidate stud shows 12 V only with the key ON and reads 0 V with the key OFF. Recheck after moving the harness to avoid intermittent contact. [Elektroda, Staszek49, post #16713152]
I already connected DRL to parking lights; is that okay?
That can work as a dim/disable signal, but you still need an ignition source for automatic on/off with the engine. Move the power sense to an ignition‑switched feed and keep the parking‑light line as the off input if your controller supports it. [Elektroda, Staszek49, post #16713152]
Any safety reminders for daily use of DRL?
Do not rely on small LED bars in heavy rain or low visibility. Switch on low beams to activate front and rear lamps. Community feedback highlights poor visibility from weak DRL strips and urges using proper lighting in bad weather. [Elektroda, opornik7, post #16713172]
car chassis etching on asphalt. It is a pity that the police do not get on the ass of these ingenious Dobromirs.
