Datsun B110 headlights are fused through the fuse box. No relays are used. Original Specs for headlights are 50/40 watt (standard large round headlights). From the fuse box "Battery" side (always hot, not dependent on ignition key position), through a 15-amp fuse the circuit goes to the Light Switch. From the Light Switch it goes to the Dimmer switch on the column. From here -- depending on the position of the Dimmer lever position -- it goes to either the low (DIM) beam of the headlights or the high (MAIN) beam of the headlights.
Also see: Headlight Specifications
Earthing
The headlights are grounded via the main wiring harness
Completing the headlight features is the "High Beam" light in the instrument panel. This is connected to the high-beam circuit to light up a visual indicator on the dash when the high beams are on.
So the headlight circuit has these components:
- Two identical headlights
- (Standard 12V "large round" type used by all makes of older vehicles)
- 15A Fuse in fuse box
- Light Switch
- Dimmer switch (T/S & Light Switch on steering column)
- High-beam indicator lamp in instrument panel
- Wiring and connectors
- Relays are NOT used
Pinouts
Light Switch connector
| R | Headlight hot feed
from R wire of fuse box ('L' terminal)</td></tr>
| R | Headlight circuit hot Output
<li>To RY wire of Dimmer Switch |
| n/a | no connection |
| n/a | no connection |
| GL | parking lights hot feed
<li>from GL wire of fuse box ('PT' terminal) |
| GL | parking lights circuit output
<li>to GL wire of headlights
<li>to GL wire of running (parking) lights
<li>to GL wire of Instrument panel | </table>
 light switch wiring diagram
Position Connections
| OFF | no connections | | Pull stop 1 (halfway out) | GL to GL (parking lights)</td></tr>| Pull stop 2 (all the way out) | <li>GL to GL (parking lights)<li>R to R (headlights) | </table>Headlight connector
| B | Ground | body connection | | RW | (high beam) to one RW terminal of Dimmer Switch | only powered if Dimmer lever is forward | | RB | (low beam) to RB terminal of Dimmer switch | only powered if Dimmer lever is back |
Dimmer Switch (in T/S & Light Switch unit on steering column)
(headlight section of switch listed here)
| RY | Headlight hot feed | From R wire of Light Switch</td></tr>
| RB | headlight low-beam | <li>To RB wire of headlights |
| RW | headlight high-beam | <li>To RW wire of headlights
<li>To RY wire of "MB" light\* in Instrument panel |
</table>
\* Labeled "Beam" for 1971. The other side of this light is grounded.
Passing Light Switch
A passing light feature was an option for B110. If your turn-signal lever has a push-button on the end, it's the passing light switch. Push it in, and the headlights light while it's pushed in (regardless of whether lights are on or off).
This is composed of two parts:
- The switch itself is part of the turn signal (on the steering column).
-
 
- The relay. 1200s don't use headlight relays, except for this optional Passing Switch. It looks very much like the Horn Relay.
- 25230-89912 RELAY-passing lamp (4-connector relay on early models)
- 25230-89905 RELAY-passing lamp (3-connector relay from 1971 Apr)
- 26320-14800 RELAY-horn (has 3 connectors, located by Coil)
-
 
Note that this just wires in series with the standard wiring. From the 'L' fuse to the high-beam wiring, the switch bypasses simply the regular switch, firing the Main Beams.
Passing Light Switch circuit
- The red circle indicates the part of the T/S switch that is different from a normal T/S switch
Relay
You may add a relay to improve the power to the headlights. Some club members report the headlights are much brighter when wired up this way.
Discussion
Harness Kit
If you have more money than time, an Relay wiring kit is really easy:
Take the new harness:
1. Connect HOT wire
2. Ground/earth the relays
3. Plug into existing headlight connector
4. Plug harness into headlights
Your'e Done! Only $129 USD
Painless Wiring Headlight Harness with relays
|
|
|
![[Datsun 1200 encyclopedia]](/wiki/upload/wiki.png)