Daytime running lights

[Camar068]

Needed to update this post with at least the latest ckt.

Also, note this diagram doesn't show the oil pressure switch (ground) on the relay on the left (DRL).

Now here's the next question. I'd rather not add another sensor to fail to the vehicle (oil pressure switch). Is there a ground or even a positive signal, from an LS PCM that can be used? It would need to be one that only comes on when the engine is actually running.

You must be registered for see images attach

 

[yevgenievich]

Tach signal or maybe just use drl module from newer truck

 

[Snoots]

I have to start over, the SPST relays are solid state and rated for AC output only.

BS. Relays are going to pass DC voltage UNLESS the output has an in-line capacitor or diode to ground. They will work. You just have more to wire.

 

[73c20jim]

I have a 73 automatic. Only uses 4 terminals on 7 pin NSS. Two not used seem to be connected when truck is in D, D1, D2. I'm going to use this to activate new DRL circuit.

Need to test theory.

 

[Camar068]

was thinking the fuel pump power would suffice, but then the lights will be on during starting. Back to the board lol. Getting closer though.

 

[roundhouse]

Could use a oil pressure or a switch activated by engine vacuum

And it might be easier to use one of the relay harness from LMC or summit that’s designed specifically for your model truck to remove the big power from the old headlight switch

I’ve installed those relay harnesses on both my 76 K10 and my 74 bronco and they make a noticeable difference in the light output and I was able to buy a plug and play harness that had the correct plugs


Biggest question is why anyone would want the daytime lights

I don’t like them
If I want the lights on , I can Can them on , and sometimes I run them if I’m on a two lane country road but if I’m on the interstate I’d prefer no lights

If I’m backing into my driveway late at night my lights shine right into the house across the street and I always turn the headlights off so I don’t disturb them

And sometimes you might want to be able to drive with no lights at all ....

 

[Crispy]

How about a universale DRL control module? 4-5 wire install

https://www.amazon.com/Mobilistics-Daytime-Running-Universal-Control/dp/B01IFWNSFI
https://www.amazon.com/Automatic-Headlamp-Controller-Automotive-Assembly/dp/B00EUVFIYI

Havent used either so I'm not recommending them in particular, just suggesting the option.