Today I reprogrammed my headlights
Ever since I bought my X almost 40 years ago, switching on the headlights always was a bit funny. The side/parking plus tail lights were on with dash switch in position 1. To open the headlights I had to use the fog light switch on the center console that also turned on the high/low beams. That switch also worked when the ignition was off, but then only the headlights were raised/lowered (no lights on).
When I compared my wiring with the wiring diagram of my Haynes, it was uhm… different. For starters the original used only one relay under the dash instead of two as was the case in my X. But the Haynes’ version does not do what I want either.
I want to use the side + rear lights as daytime running lights (with 20w bulbs in the front side lights to increase visibility). Want to be able to run without any lights and want the headlights up (and dashlight on) only when I need high/low beam. All that with just the one dash switch.
The Haynes version does not do that, in position 1 all lights are off, in position 2 the headlights go up. What headlights are on depends on the high/low beam selector stalk on the steering column (none/low/high) but side lights with the headlights down is not possible and the green control light is on even if the low beams are off.
So I came up with the following modification, using a 5 pole switch-over relay:
View attachment 81592
It works as follows:
Turning the ignition on with the switch on the dash in position 1 switches on the side and tail lights through a relay. The commanding circuit of the relay also turns on the interior illumination (buttons etc.), the instrument panel illumination stays off.
Switching to position 2 raises the head lights. Which headlights are on depends again on the position of the high/low beam stalk:
- Up is headlights are off (side lights stay on)
- Flat is low beams plus green control light
- Down is high beams and blue control light
Similar to the other relay, the commanding circuit is now used to turn on the instrument panel illumination.
None of the high(er) currents are switched through the ignition.
Switching back to position 1 closes the lights and reverts to daytime running lights. In position 0 none of lights are on.
Turning the ignition off turns off both relays, kills all the lights and the 5th pole energizes the circuit to lower the headlights. So the headlights are lowered automatically when the ignition is turned off (and can’t be raised until the ignition is switched on again).
Now I can use the fog light switch to actually switch my rear fog light, for my safety.