Driving lights can be switched ON/OFF using the existing switching in the vehicle if it's fitted with fog lights....
I was wondering where to install a driving light switch with my 2015 2.2CDR Santa Fe and realised that when it was “legal” to use high beam and driving lights then I might as well also switch on the fog lights! On this basis I tapped the high beam circuit to “ partly” energise a relay (Relay 1) which switches the driving lights connected through a fuse to the battery.
Relay 1 is fully energised by a second relay (Relay 2) which is powered by the existing fog light switch.
Thus, with the high beams ON, and switching the fog lights ON, Relay 2 activates Relay 1 ( via connection between#87 Relay 2 and #86 Relay 1) which powers the driving lights. (see below)
In practice, with high beam ON, the driving lights are operated by switching the fog lights On/Off.
If the high beam is switched OFF then high beam and driving lights are both extinguished, leaving low beam and fog lights ON. Fog lights can be simultaneously extinguished by flicking the fog light switch ...on the Hyundai all lighting is controlled on the " lights/indicator stalk ".
Fog lights and high beams still operate independently nevertheless.
Obviously this arrangement does not provide all the options for independent operation outlined in other posts, but it gets the job done.
There is a subtle difference with the Hyundai…they “switch” the earth! Nevertheless the principle should hold. I mounted the relays in a void behind a panel on the firewall which houses the windscreen wiper motors etc. Am thinking there’s probably a way to put them in the fuse box which seems to have plenty of extra space ….
Usual caveats apply re. liability…but here are the relay terminal allocations I used
Relay Terminal details:
Relay 1: #85 high beam feed
#86 connects to #87 of Relay 2
#87 + terminal of L.E.D. driving light
#30 + terminal of car battery
Relay 2: #85 Fog light feed
#86 Fog light return
#87 Connects to #86 of Relay 1
#30 High beam return
MY99 RR P38 HSE 4.6 (Thor) gone (to Tasmania)
2020 Subaru Impreza S ('SWMBO's Express' )
2023 Ineos Grenadier Trialmaster (diesel)
Bookmarks