what does this wiring harness do? i dont know what a relay does.
i am having a problem with my headlights tho, i installed silverstars and ever since then i can run my lights for about 5-10 minutes then they flicker on-off and i have to turn my lights off for a few seconds for them to be back to normal again... what gives?

This mod reduces the amp draw/wear & tear on the headlight switch because so many things on the truck are run simultaneously through the headlight switch. It also increases the voltage input to the headlights, which in turn gives you more lighting potential and a higher wattage output potential. i think that sums it up. As for what relays do heres a good site to illustrate it and theres some good info here:

http://www.bcae1.com/relays.htm

Hey Jim,

I am going from a single bulb assembly to a dual bulb (sport) assembly, for truck in my sig. I am assuming that I just wire in the second headlight connector (high beam only) in conjunction with the main (High and Low) connector.

BTW Absolutely fantastic write up. Simply remarkable that someone would take that amount of time to help others. I would like to know where your donation jar is!!!! I have a what I saved to put into it.

Stock headlight blues..........
 

I have just recently gotten into researching headlight information. This writeup has really made me realize that I'm not alone in experiencing dim factory lighting. Just recently I have lifted the front end of my pickup 2.5" to level everything out. My dim headlight situation has gotten worse! I can barely see anything in front of me going down a lighted freeway at night. Often I find myself double checking to see if my headlights are even on! Yup, they are..........but it doesn't seem like it. I find my current lighting situation annoying and down right dangerous. I plan to change the wiring and add relays as explained in the sticky.

Speaking of headlights.........Does anyone know what kind of headlights are used on the silver 1st gen featured on the front page of DIESEL WORLD? I really like the looks of those headlights and would like to "modernize" my pickups headlights.

Nice write up. I did this on my 89 ctd and wow it really improved the lighting i even think it made my dash lights a little brighter.:cool: I even made a tray to mount all of my electrical on it.

I don't know about the headlamps, but here is a good source for the components needed for your lighting harness, in addition to a lot of good info regarding lighting for your tuck ->www.danielsternlighting.com

There is an email he sent me in response to my inquiry here -> https://www.dieseltruckresource.com/...d.php?t=227555

It is very long, but he gave me very specific solutions to this problem.

Hope this helps.

wish I'd noticed this before! ... my headlight switch and harness fried two years ago so I replaced the whole mess with rocker switches and relays; works great but don't borrow my truck without a 15 minute briefing on all my "silly circuits", and not color coded so I need to reverse engineer it every time I'm in there

Great write up man, I showed it to my brother(he's a small engine mechanic) and he said you should go work for Cub Cadet because the make crap wire harnesses.[laugh]

I'm so what new to this site on here once in awhile but never posted. My question is will this work just fine if I where to put in after markert headlamps with brighter bulbs or run HID lights without melting anything?

thanks

Yes, the relays will handle the added current.

I would go a step further and suggest that you NOT upgrade the headlights until you have put in the relays, because the extra current from the high powered headlights will melt the headlight switch faster.

Your headlights need adjusted way down. You probably have oncoming traffic thinking you are running your high beams.

I'm glad I read this, I would have been scratching my head trying to figure out why I wasn't shutting off my low beams.

How to Adjust your Headlights
 

Here is how you adjust your headlights,

It is best to do this when it is dark.

Find yourself a nice wall or garage door and a flat driveway, drive your truck up to the wall or door and with some electrical tape and a tape measure find the centerline of the headlamp and transfer it on to the wall or door and put a piece of tape for the height and width for both headlights and put a +, now back up your truck exactly 25 feet and square from the wall to the face of the headlamps.

Next go to the wall with your tape measure, measure down 4" from the centerline height mark and put a piece of electrical tape about 8" horizontally for each headlamp.

Turn your lights on low beam and have someone stand in front of one blocking all of the light and now look at the wall and look for the hot spot from the lamp (you will see a hot spot with an obvious horizontal flat line) and then using the 2 Torx adjusting screws move the beam up down / left to right until the hot spot is at the line that you put on the wall and directly ahead of your truck.

Now move to the other lamp and do the same, this will adjust your headlights close enough to the required 1/4" drop @ 25feet

What you just did was to adjust your headlights 4 inches below the lamp centerline at 25 feet.

At work in our underground parking I have this all marked out on the wall and lines painted on the ground so I just drive up the lines on the ground turn on the lights and check my adjustment and nobody has a clue what they are for.

This is not really as complicated as it sounds, shouldn’t take more than 10 minutes to set up the marks and adjust the lights start to finish.

Jim

Thanks again awesome write up just got done wiring everything up and can't wait to see the difference.

The dual bulb assembly, what does that run, 2 small sealed beams per side? Or it is housings for more modern bulbs? Where do you find them?

Jim Lane, on the semi, when I have to change bulbs(large square sealed beams), I adjust them way down and directly forward, with the left one turned in just a little, then adjust them up over the next few nights of driving til they put a good pattern down on the road, on the low-beam side. I never was happy with the shop's adjustments of the lights when I was at Schneider.