Do your headlights seem dim when driving around at night? Would you like to have a huge improvement in your nighttime vision? If so, this article will describe how to upgrade your wiring, and optionally, to convert your headlamps with H4 conversion lamps!

As you are probably well aware, the headlamp wiring that comes stock on many of the early 80's to mid 90's cars is of a very small gauge and full of points of resistance. For example, on the '84-'89 Daytonas, the power for the headlamps follows a very long path; it comes from the battery to the headlight switch, through the steering column dimmer switch, then through a wire that splits into two and goes all the way around the engine compartment finally reaching the headlamps. Obviously this is not the optimal setup, so the following article will show you how to upgrade you wiring for more voltage. In my car, this procedure increased the voltage from 11 volts (a 3.2V loss!) to 14.1 volts (only .1V loss!). While 3.1 volts may not seem like a lot, headlamp output decreases exponentially with lower voltage, so it makes an immense improvement when driving at night.

Parts Required

1. 2 Bosch Style Relays

2. 12 or 14 gauge wire for the lamps (Multiple Colors)

3. 18 gauge wire for the relay control wires

4. 2 Inline fuse holders

5. 2 H4 Conversion Headlamps (Optional, but highly recommended)

6. Soldering Iron and solder

7. Wire cutters-strippers…

Schematic

This is a schematic of what the completed circuit should look like when it is finished. Refer to the instructions below for more details and pictures.

Instructions

1. The first step in this project is to determine if you are going to use the original headlamps or if you are going to upgrade to a H4 conversion headlamp. The H4 is much more efficient than a sealed beam lamp and therefore will produce a much brighter beam on the road. The lamps I recommend are the “Free Form 165mm Hella H4 Conversion Lamp” from rallylights.com. These are a cross between American DOT and European E-Code lamps, and are still DOT approved.

2. Start by unhooking the battery and removing any induction tubes, etc. that might get in the way of the wiring behind the battery. At this stage you should also scope out a location to run the new wire from the Drivers side to the Passengers side. I chose to run mine under the radiator core support.

Picture showing the new wire