I currently have 2 pair of foglights wired with two relays and to the high beam wire as the trigger line.
However I would like to re-wire the trigger line so that I can turn on the foglights anytime I want, what would be a good source line for my case?


Thanks.

 

Power Line:
Run a power line directly to the relay from either the fuse box, or better yet, take off of the starter solenoid hot terminal (from batt) but be sure to use an inline fuse rated for the lamps as well as heavier wire (12ga).

Trigger Line:
Run power from a fuse box hot terminal to an interior switch. Then from the opposite terminal of the switch to the relay. The opposite term of the relay is grounded. Check the fuse box for terminals that are only on with the ignition switch in the "on" position. As this is just switched current you can use lighter wire (14/16 ga).

This is how I have my Lucas SLR700 & SFT700 lamps wired. Each pair on a separate switch.

 

sorry but how do i check the fuse box for terminals that are only on with the ignition switch in the "on" position?

 

If your harness is original and unmodified, the following excert from an article about adding a circuit may help...

May issue of Classic Motorsports has an article about adding circuits for a set of air horns and a set of driving lights in a Midget. "....and those of you that speak Lucas know that the colors all mean something: White is switched (on when the key is on), unfused; green is switched, fused; brown is unswitched (always on), unfused; and purple is unswitched, fused."

or...with the ignition off, take the cover off the box (if you have a cover) and use a volt ohm meter set to volts (a range that includes 12 volts) Take the black lead to a ground....an unpainted bolt or spot on the engine. Touch the red (positive) lead to the metal at either end of the the fuse. If you get voltage...that's an 'always on, fused' .... no volts = switched & fused. Try again with ignition on to be sure everything is right.

You should see white (switched unfused) on one side of a fuse (or fuses), and green meaning switched and fused on the other side of the same fuse. You want that green side....but use an inline fuse on your line to be 100% safe.

If your colors are messed up don't be surprised. Who knows what kind of hacks happened to the wires. But play with the volt meter and you'll figure things out. Bottom line is one side has (should have) switched and unswitched power coming into the box, and the other side has switched and unswitched FUSED.