HOW TO Build a DIY Four Light Headlight Relay Harness for $30 Episode 229 Autorestomod 

This is the best set up I have seen yet, love the quick disconnect for bypassing the relays.

You can do it with a 4 pin and a 5 pin also. Power the 30 on the 4 pin and 87 to power the 30 on the 5 pin. Trigger 86 on the 4 pin with low beam and 86 on the 5 pin with high beam. Tie both 85's to ground, low beam to lights is 87A on 5 pin and high beams is 87 on 5 pin. A 4 pin relay is on/off where a 5 pin is one or the other, with 30 powered and 86 not energized power flows through to 87A, when 86 is energized flow switches over to 87. This gives you high and low from one relay.

Nice to see some love for the 68/68 Fairlanes. I need to do this to my 68 Fairlane.

Very timely video, Jeff. I need to set up headlight relays (two bulb only on a tractor). Your overview filled in several blanks in my plan.

what I did to hide the relays was to get a old voltage regulator and gut it, then mounted the relays inside and made a cut relief for the harness. I mounted it about where you did though. Good job tho !!!!!

You can also fill the back of the plug side with hot glue or silicone to seal them and then use dielectric grease on the plug to the relay.

Thank you for this tutorial, the high beams started flickering on my Lincoln Continental after I hit up the car wash...

I made a headlight relay harness for my 1968 Mustang but I used a male headlight plug to connect to the original wiring instead of cutting the harness to go to the relay then I ran wiring to both head lights with new ceramic headlight plugs for the added heat of halogen headlights. The headlights are way brighter than original and I didn't have to cut the harness.

just came over from your Ford Electrical Problems video....bring back the mop top!!!!

Great video, sort of vehicle specific, but that's okay with me! Gave me some ideas to apply to my '05 Prius tomorrow! Going original HID headlight to halogen. Needs a relay. Thanks! Soldering comment: you did it but didn't say it... you let the heatened wires melt the new solder instead of having the solder iron melt the solder. Great! Then shrink tube, etc. That's how I like to join wires!!

I would DEFININITELY stay away from the cheap relays, Chinese relays whatever. And also keep a couple spares in the car. Best thing to do, go to the junkyard. Chrysler Minivans from the '90's used that basic Bosch relay for bunch of things and they plugged them into the fusebox right near the column. They're high quality made in Germany OE relays. I grab a handful every time I go and see one of those. I use 'em for everything. Had the cheapo ones fail on me before on night on a trip. Burned up at 1/3 the rated load. Not good.

If you are running 100 watt halogen bulbs on high beam you will need a 40amp relay for the high beam relay and 40amp fuze or breaker

86+ i did not want all 4 lites on all of the time. i bought the 4 lite harness for the mustang shelby.Has ceramic lite plugs. from your pals at n.p.d mustang catalog.*11653-2b redline lumitronix $62.78 plugs into one low beem lite plug.worked good in my 70 fairlane with all halogen bulbs.

There are those who say even when you install a CB Radio or 8-Track in your car you should use a relay. Yes, I'm old.

so great and clear way to explain thanks

Thanks that's amazing great video channel nice ideas I like it blessing

Thanks for all the great little tips. Lots of knowledge transfer! You sid this was specifically for Ford products, It seems like it would be pretty applicable to GM products as well. Any particular gotchas you had in mind if I apply this to my 67 Firebird?

If I could make a suggestion, I know this is 7 years late, the way I do it is to fabricate the whole relay harness with new wires and 4 new headlight connector terminations, preferably the ceramic ones, and leave the original harness completely intact. Then run 2 wires to trigger the relays (one for each) from one of the closest old OE low beam headlight connector and crimp or solder some spade terminals on and just plug into the OE headlight connector. This way you can completely revert back to stock if you choose or there's a relay problem or whatever by just plugging the OE headlight connectors back in. I've NEVER had to cut an OE harness yet. For heavy duty off-road lighting or high performance, yeah, I usually use heavier gauge wire and nice relays and ceramic headlight connectors. But for most cases with OE or Halogen 55w or 65w bulbs it's so easy to buy any one of the many 'pre-wired' kits and modify it as needed, usually just altering the headlight and signal terminations. Also, with these old cars sometimes it's better to feed the relay power (30) right from the back of the alternator. Usually the alternator charge feed to the vehicle wiring is inadequate also. You could just run an 8ga jumper from the Alt stud to the battery or starter solenoid. The real point of doing this is to get full alternator voltage (14.4-14.7v) to the headlights. Most old cars only see 11.5-12.5v if you're lucky. The headlights will be so much brighter.

Very good!

Hey Buddy, thanks for the vid. I got a '79 Lincoln and my relay prob got fried. It has a 5 pin relay, but noticed that the wires(green/black, red/yellow, red/black) to the relay are extremly hot. I want to use this vid to modify my headlight/high beam harness but not sure which relay i should pick (40A?)... just want to be sure that my car doesnt get a fire...

Also, isn’t it there’s a relay already for the headlights? What will you do with the old relays?

very good info much appreciated

So build it for $30 or buy it online already made for $15 or $20

Will this work on modern cars if you want your headlights to become brighter

LOL! I judged you man when you broke out the crescent wrench just about the time you said , "don't judge me!". ME:what kind of mecha YOU: Dont judge me.

Do you think i can run halogens in my 1977 Ford ltd ? Without using a relay.

got a motor home every things works but heat and air and no spark, can i build a harness just for that.

Very good show but, stay on the topic man. Stop 🛑 wonder 💭 off.

I wish automakers would put the dimmer back on floor where it belongs..

If you can tear the tape with your hands then it's shitty tape

get a hair cut