If possible, could you try to do a before and after picture, like wolfie? Im excited to see the results. Brightness is just an added perk to it. Safety by lightening the load on your electrical system is worth it alone. Cant wait!

 

my pictures just show low beam vs high beam with lows on. i didn't take any before shot. i could if i want since all the stock wiring is still in tact but i live in town and it is hard to find a nice place to get some good pictures. now if you are interested in how i wired i the low beams to stay on with the high beams using only 2 relays this is how i did it. i pretty much used 12 gauge wire for every power wire.

 

Very cool. Thanks. Maybe I was thinking of your reverse lights where only one is on a relay. Sort of a before and after, I guess.

 

you can compare the left backup light to the the right one. the left one is on a relays and the right one is not .

 

i would have done before pics but I was too excited to GIT ER DONE! I did it on Saturday, and it is NIGHT and DAY! My headlights now are WHITE and probably at least 30~40% brighter. Even in the day light when I tested it with a jumper, I could see and feel the difference. On the non relayed low beam, the colour was more in the yellow spectrum, on the other one I ran thru the relay for a test, it was WHITE and hotter from a foot away than the other one. As well it was noticeably brighter. I did the mod and that night when sitting on my access road, I could see more on the sides, and at least 1/8 a mile further down the road, And this was with the dim lamps only on. Usually I could only see that far down the road with the brights. And even then they weren't white like they are now. AMAZING difference. I can take pics and draw a wiring diagram of how I did it if you want. What year is your truck?

 

he has a 78 w350.

glad it has made such an improvement. did you wire your low beams to stay on while the high beams are on or is that going to be a project for the future?

 

i installed both Bosch relays on the drivers side inner fender well. I left the stock headlight socket alone so I can use either or both if I loose a relay and the spare I carry in the glovebox fails. I unplugged both headlight sockets and use the low and high beam from the drivers side to pull each of the relays. I made jumpers out of 14ga to pull the relays so they are about 6in long each. I also had to make ground jumpers for the headlight since with the plug unplugged, the ground was no longer hooked up. Then I used 12ga to run from the battery into the relays, and then to the low beams on both sides as well as the high beams on both sides. When I tested the voltage alone going to the headlights stock, it was 12.4v, after the mod I get 13.8~14.5 to the headlights. That shows how much voltage drop is in the stock harness/switch. Not only are they way brighter but I am sure the switch will last a lot longer since the load of the lights themselves is taken off of it now.

 

sounds like you had a pretty bad voltage drop if you were only seeing 12.4v at the headlight socket with the truck running.

 

at most it was 12.8 and that is because the voltage drop through the stock wiring is pretty substantial. Which is why this mod works so well. This was with the headlight on btw.

 

i only saw about 0.5V drop at most on my 81 but i looked at some of the newer wiring harness and the stock ground wire is pretty skinny apposed to what is used on my 81.