I'm looking for some input from guys/gals who have installed headlight relays (i.e. wiring headlights directly into the battery)

Days are getting shorter, and I'm doing more driving both before and after daylight hours. I've been wanting to improve the lighting on my 2003 for a while now. I've read a lot of threads regarding alternate bulbs. And, yes, it seems the general opinion is that they do incrementally improve light output a small amount. I've also read that a more significant improvement can be attained by wiring the headlights directly to the battery with a relay harness.

I spent 30min or so this afternoon taking some voltage measurements on my vehicle. And I collected the following.

Vehicle idling, headlights on...
Measured directly across the +/- terminals of battery: 14.1V
Measured at the bulb, low beam: 13.3V
Measured at the bulb, high beam: 13.1V

Based on my voltages above, I'm wondering if anyone here can give me any kind of input as to what kind of improvement I can expect if I go with relays?

 

It'll be like night and day! Sorry couldn't resist! My lighting increased 100% on my '84, although ford surely addressed wire gauge size from over 30 years ago. I'd say try it and report back. It's cheap and easy to do. Not sure what mine was when I did it like 10 years ago, but it really was/is a huuuge improvement on the old iron.

Frank

 

On the older trucks especially they pulled power from the headlight s/w itself causing a voltage drop. RJM before they went under made a nice harness for like $30 to pull power direct from battery had one on my 96 with 9007 bulbs. Huge difference even with the chalked lenses.

 

I did the same checks as you back in 2001 and 2003 on my own Superdutys and found the same voltage drop. Back then there ware a lot of us making or buying relayed harness to improve the voltage at the bulbs and IMO it was worthwhile. I transferred the harness I made from the 2001 to the 2003 and it's been in use since then.

If your abilities are such that making a harness is easy, go for it. If you have the wire and some of the supplies it can be done cheaply. If not, the harnesses out there were not too bad from what I remember.

Down below is my Facebook page, and in the photo albums I have a pictorial of how made mine years ago if that will help.

 

The bigger gauge wiring is more than half of the battle, along with the relay.

 

Thanks for the input so far.

Good to hear that my voltage measurements are inline with others.

I've found a complete harness -- made in USA -- that'll run me ~$90 shipped. Considering the time it would take me to run down all of the parts needed to do it myself, spending this relatively small amount of $$$ on a well-built harness is a no-brainer for me.

I'll probably pull the trigger on the purchase next week and report back the results.

Thanks again.

 

Link? Curious who is making them now.

 

do not forget to add fuses from battery. and a relay for each headlight.

 

i'll second that. I'd like to see the build materials

 

This is the harness I'm looking at. (hope the link works OK)

9007 Heavy Duty Headlight Harness - USA Wire & Seller! | eBay