Volkswagen Cabriolet DIY Relaying Headlights PDF Installation Instructions

Tools needed:
* Wire cutter, stripper and crimper
* Soldering iron & solder (optional, but recommended)
* 10mm wrench
* Small, thin flat screwdriver or small nail
* Philips screwdriver (removing the air duct at the lower valance may be required in order to run the wires to the passenger side headlight)
* Digital Volt-Ohm Meter (DVOM)
* Camera (optional)

Parts needed*:
* Two Bosch/Tyco relays (part #0332209150)
* Two 5-pin, pre-wired relay sockets for the above relays
* Two 9003/H4 pre-wired headlight sockets (use hi-heat versions if upgrading the lamps)
* Regular male-end disconnects, 14 gauge
* Three different colors of 14 gauge insulated wire (yellow, white and brown will match the OEM wiring)
* Two in-line ATO/ATC fuse holders (10 or 12 gauge)
* Two 20- or 30-amp fuses (some fuse holders come with the fuses)
* Three ring-style terminals, 10-12 gauge
* Heat shrink tubing of varying sizes
* Black plastic wire loom tubing (optional)
* Electrical tape
* Mounting hardware of your choice (in this how-to, an L- shaped bracket is made from sheet metal)
* Small black zip ties

*This parts list is for the minimum amount of parts needed. If your Cabriolet has the dual-round headlight setup, three or four relays and related parts can be used, if desired (every relay requires an in-line fuse). Relay sockets are not required, but they will give your engine bay a cleaner, more OEM look; if not using sockets, you’ll need insulated female-end disconnects.

NOTES:
1) Wire lengths are not given in this how-to because the lengths will vary depending on where you locate the relays. Always measure prior to cutting! Wire colors are also not given because color preference varies from person to person; therefore, the pictures of wires in this guide are for reference only.
2) The stock wiring is 16 gauge. If you are using stock sealed-beam lamps, 16 gauge wire will suffice; however, it is advised that you upgrade the wiring to 14 or 12 gauge, especially if you plan to upgrade to higher-powered headlights. Wiring diagrams can be found on pages 6 & 7. When stripping wire, strip just enough insulation off of the wires for splicing and/or inserting into disconnects and such.
3) These relays have two variations; know which relays you have before beginning! One relay uses two 87 terminals; the other relay uses one 87 terminal and one 87a terminal. Relays with two 87 terminals are convenient because one terminal can be used to power the driver’s side headlight and the other to power the passenger side headlight. Look at the bottom of your relays: If one or both of your relays have terminal 87a, that terminal cannot be used; instead, the two headlight socket power wires will need to be spliced into the one regular 87 terminal wire and the
end of the 87a terminal wire (if using pre-wired sockets) will need to be taped. The steps in this guide use two regular 87 terminals; however, the diagrams on pages 6 & 7 show both types of relays and how to wire them.

Before beginning this procedure, it’s a good idea to take a voltage reading at the
headlights (and photograph their brightness for a before-and-after comparison):
* Pop the hood, turn the engine on and take a voltage reading at the battery.
* Flip the headlight switch on and take another voltage reading at the battery (see voltage drop?).
* Keep the negative DVOM lead connected to the battery’s negative post and touch the positive DVOM lead to the lo-beam (yellow/black wire) headlight terminal. Record the reading (take a picture of the lights, if desired) and turn the lights, engine, and DVOM off.

Download Volkswagen Cabriolet DIY Relaying Headlights PDF Installation Instructions