Wiring in 2 relays to the headlight's
 

OK guy's this ? has been asked I don't know how many times. Who has the best head light wiring with relay's.
I decided to do it myself with $13.00 worth of parts from O-Riley's auto parts.
2 relays
16 count of the yellow spade connector's
1 30amp fuse link holder
Here is what I did.
I figured out from my shop manual that both the low & high beam work off the driver's side light, so I cut the incoming green & grey wires off the connector, then put longer peice of wire to both relay's. This will activate the relay not much load so the wire can be same gauge as factory. I didn't run a heavy gauge wire to the passenger side light but may do it later on. I don't see any reason to but you never know.
Light connector:
http://216.77.188.54/coDataImages/p/...tconnector.JPG
Here is the relay's mounted with all the connections done. The one mounted high is for High Beam the lower one is for Low Beam.
http://216.77.188.54/coDataImages/p/...137/Relays.JPG
I ran a good gauge hot wire with 30 amp fuse holder in line across the radator support to the battery and split off to both relay's. Then ran two grounds for each relay. I then added some length's of wire from each relay back to the connector on the head light. Took me 2 hrs to do it. Hope this helps other's who want to do this upgrade. I used butt connection's or spade connections with black tape on everything and wraped everything in black tape when done.

http://216.77.188.54/coDataImages/p/...37/HotWire.JPG

Re: Wiring in 2 relays to the headlight's
 

Here's a schematic that may help. You should run a heavier wire to both lights. I found another so I included it.

Re: Wiring in 2 relays to the headlight's
 

Looks great! Good job! Someday I will do mine. I am surprized the parts were only $13! O'riles must be good. I did the converion on a '76 I had. Makes big diferance!

Re: Wiring in 2 relays to the headlight's
 

Looks good! You got part numbers for the relays?

I'm wanting to do this to mine. In the middle of a frontend swap. And auto to manual trans. changeover. I got the frontend swap done befor the snow. But looks like it will be March now for the rest.

VetteVet: Thanks for the diagrams.

Re: Wiring in 2 relays to the headlight's
 

I would mount them a little higher on a driver truck, they'll get splashed with a lot of water there. Imounted mine on the side of the Aux battery tray on the longhorn, haven't done it to the burb yet.

Re: Wiring in 2 relays to the headlight's
 

Re: Wiring in 2 relays to the headlight's
 

The whole reason to install relays is to provide a higher amperage to your lights thereby increasing the amount of light. This also keeps the increased amps out of the headlight switch and corresponding wiring.
Sometime ago prior to getting hooked on these trucks I owned a vw jetta gli. I installed a set of european lamp assemblies with H4 bulbs that were rated at 85/80 watts. I did much of the same except that each headlamp utilized two relays, one for high the other for low for a total of four relays. The factory wiring was used from the switch to the relays then from the relays I used 10 guage wiring for both the 12v and ground connections. Seems like overkill but I wanted to be sure that when I had my high beams on I wasn't going to melt any wires.
To calculate the amps your headlights will draw use the following: Amps=watts/volts. So for a 55/45 headlamp using the equation gives us: 55/12=4.58. Together your headlights on high beams will draw approximately 9amps of current. Using that information you can now select the proper gauge wire to use from the relays to your lamps and your grounds...

Good luck!

Re: Wiring in 2 relays to the headlight's
 

Well since we are talking bulbs and such...can some one tell me what kind these are?
I took them out of my daughter's car when I replaced the head light assemblies. This is on the bulb's:
3A HB2
9003
12V
60/55 watt
http://67-72chevytrucks.com/gallery/data/580/Bulbs.JPG

Will they work in my truck you think? What would be the "+" of using them?
Here is what I have now. Same watt's.
http://216.77.188.54/coDataImages/p/...riBarlight.jpg

Re: Wiring in 2 relays to the headlight's
 

Those lamps are an attempt to mimic the HID lamps on European cars….will look out of place on your truck IMO. That type of lamp will be brighter. Get one with a higher wattage like 85W low beam 100 high. The stock ones are 65W low usually.
s/t

Re: Wiring in 2 relays to the headlight's
 

Re: Wiring in 2 relays to the headlight's
 

You can find out what the wattage they are by the pn# and call the local parts store like AutoZone. Not sure what you have now, but it’s could give you something to try if it’s brighter (higher wattage). The blue hue will be a little deceiving though. Hella makes some nice replacement bulbs for your application. And they make them in all kinds of wattage. Will work nicely with your relay mod.:metal:
s/t

Re: Wiring in 2 relays to the headlight's
 

9003's. There are several numbers that have to do with which bulb is correct for whichever application your intent is. They may/may not work in yours. Seems like I recall that Hella's use H4 bulbs. Those you showed are H2B's. I got this info from reading the numbers on the metal base of the bulbs, so I didn't make this data up. My Tundra uses 9006's.

Re: Wiring in 2 relays to the headlight's
 

Re: Wiring in 2 relays to the headlight's
 

I did the same to my Jetta. Very easy job. I could light up road signs for the car in front of me from 500 ft behind them. You definately don't want to play high beam games with someone who has the lights hooked up like this. It takes the load off of the switch (not made for that much current) and lets the relays transfer the voltage directly to the lights. A fast 8 point buck was the only thing that stopped them. He stopped too. He died and my lights shined no more.

Re: Wiring in 2 relays to the headlight's
 

I haven't even drove it at night yet, but knowing it's got the relay's makes me feel better!:lol::lol::lol:

Re: Wiring in 2 relays to the headlight's
 

Re: Wiring in 2 relays to the headlight's
 

Going back and reviewing the schematics and other references, I realized that the heavier wires are needed just to feed the relays. I think you would be fine with the OEM harness from the relays to the lights. It certainly wouldn't hurt to run heavier wires but like you said you would have to rebuild the connectors at the lights.

Re: Wiring in 2 relays to the headlight's