Headlights only on while engine running

[85 CA SIERRA 1500]

Hi fellow Square Body people,
I was wondering if any of you have wired your trucks so that the headlights will only light while the engine is running (and the battery is therefore charging)?
Was thinking this might be a good way to never forget to turn the lights off if for whatever reason they had to be turned on in the daytime.
All the best,
Tracey>>>>>>>>>>>>>>>>>>>>>>

 

[75Monza]

Be easy to do with a basic relay that coil is powered by accessory power or switched power with the main power lead to headlight switch through the contacts.

 

[Camar068]

Daytime running lights schematic that I drew up. I haven't done it yet...need to get off my ass lol.

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[85 CA SIERRA 1500]

HI Gang,
Hello again, just a quick update.
So I wired the trigger terminal of a 30amp relay to the choke wire, thinking that would do the trick and only energize the relay while the engine was running.
Well, it seems that the choke circuit on my truck is hot whenever the Ign. is on.
I always thought that the choke wire was only supposed to be hot if the oilpressure switch had pressure, meaning that the engine was running, thinking that the previous owner may have bypassed the oil-pressure switch and wired the choke to an Ign.-Hot circuit, oh well, at least the power to the lights is killed anytime the Ignition is off.
As an aside, I re-wired the headlights with 10 gauge direct from the battery positive and then through the relay and man what a difference in light output. I never realized just how much voltage drop there was going through the stock OEM wiring.
All the best,
Tracey>>>>>>>>>>>>>>>>>>>>

 

[ali_c20]

Relay harness is the way to go...brighter lights and less load on the old wiring. I bought the relay harness form classicparts to save time.

 

[71RAT]

Relay harness is the way to go...brighter lights and less load on the old wiring. I bought the relay harness form classicparts to save time.

2x's I just looked at their harness, for $30.00, by the time you round up the plugs, ends, etc. That's the way to go!