Homeade Hella Wiring Harness

[85Chief]

I picked up a set of Hella 500 fogs for free, but they had no wiring harness.

I've been looking at Fitch's wiring writeup here ( http://www.naxja.org/forum/showthread.php?t=60117&highlight=wiring ) but I don't want to do anything nearly that large even though it's an excellent write up.

My question is what all would I need to wire it up to a simple switch. Me and electricity do not get a long very good....

I would need wire running from the battery to a fuse, then to a relay, then to the switch and headlights correct?

Would this fuse holder, and relay work for what I am wanting?
http://www.radioshack.com/product/i...&cp=2032058.2032234.2032302&parentPage=family
http://www.radioshack.com/product/i...&cp=2032058.2032230.2032277&parentPage=family

What gauge wiring would I need from the battery to the relay, and then from the relay on?

I think that is all that I need help with .

Thanks
Clay

 

[5-90]

What bulbs are you going to be running?

I have Hella 500's and 550's (fogs and driving - I don't recall which is which,) and I wired them up with 14/2 SJOOW from the hardware store. "14" refers to the gage of the individual wires, "2" is two wires per cable. "SJOOW" is a service code - basically, it means all-weather rubber insulation, oil resistant.

Running them with fine-strand 14/2 makes it a LOT easier to pull wiring (since I only have to pull one 3/8" cable, and then I can strip the ends when I get them where I want them...) to each light. I pulled power from a distribution post I have anyhow (to keep accessories from being wired directly to the battery, and to make it easier to disconnect and change the battery,) and I also pulled power FROM the post, THROUGH the relay "trip" coils, and thence to two toggle switches I installed in the console. The other side of the switches goes to earth - so the circuit is completed with the switch ON, but broken with the switch OFF.

If you're thinking of going somewhere past 100W (I'm not sure those housings can handle that sort of heat for long, but it's worth checking,) let me know, so I can give you a better "guesstimate" for wiring gage - but for under 100W per bulb, 14/2 SJOOW is just fine, and should be had at the hardware store. If you can only get wiring without the "J" in the service code, you can use it, but it's not oil resistant (so you'll probably end up running more wiring to each light to keep it out of oil's way. It should tuck neatly in the bumper anyhow, and you can drop it into the bumper right near the battery.)

For the relay "trip" circuits, you can use any size of wire - I just happened to use some 18/2 SOOW that I had from another project. The relay "trip" current can be measured in milliamperes, which is why FitchVA decided to use Cat5 cable for the switch leads (which makes sense.)

The switch can be easily installed anywhere convenient. If you have an open slot for a switch down by the steering column (the OEM ones in the dashboard,) you can get an OEMR rocker switch that turns ON/OFF (use a rear window wiper switch, f'r instance) and have a "clean, factory" look to the job. Or, you can use a toggle, and install it anywhere you can drill a 1/2" hole and have about a 2" cube behind the panel for the switch and wiring to fit into.

If you get a hardware store toggle, I highly suggest getting one with screw contacts, rather than spades. With the vibrations we tend to see, spades can work loose over time, but I've not noticed this with screws. Why they won't do this anywhere else eludes me, but I've had it happen on switches just often enough that I won't use "push-on" connectors on switches anymore. I prefer using screw lugs anyhow. Any rating will work - since you're going to draw 1/5A MAX tripping the relay anyhow.

5-90

 

[aroncull]

Lately i feel like i am reading everything you say 5-90, very good..
I would like to hear more about the distribution post you created.. my wiring isnt rats nest, but i still want to clean it up and get all but my amps off of the battery.. to messy with my headlight harness, amp, driving lights, alarm,ground etc.. with a winch and more on the way even my side posts wont help..

85chief all i can contibute to your question is that i would think very hard on where you want to mount the switch and consider one that lights up fairly well as you will likely leave your lights on and run the battery down at some point ..."murphy" n all and at least with an led switch you will see/remember that its on... hopefully
But again going by 5-90's rec i would look for one that has srews instead of spades. Factory is nice you could even change the light behind the switch.... i think... woo its late..

aaron

 

[85Chief]

Thanks for the response guys...

I believe the bulbs are only 55w, and I don't plan on changing them.

I too would like some more info on your distribution post. It sounds like a good idea.

I will also look into the screw on posts...after you mentioned how easily they could work themselves off, I might as well do it correctly the first time.

aroncull- I think I will wire these lights up to the parking lights that way I can switch them on with either the low or high beams. I live out in BFE where I can use them almost all the time at night because lack of vehicles.

 

[5-90]

I got it from Gall's years ago (www.galls.com) since it's intended for police cars. I've found another distributor, but you can only order from them in bulk - so it might be getting added to the WiP product line (how many interested parties?)

I've run 4AWG to feed the post, and then split everything off the post from there. I can get them in "surface mount" (insulated, bolt them down and stick all the wiring to it) and "pass-through" (drill a hole in a panel, and the post sticks out on two sides. Convenient for going through firewalls and such) - let me know how much interest for each, and I'll see about coming up with price points for everyone.

For making sure they go off when you turn the key off, take a pilot line from the ACC position on the keyswitch, and use it to trip a relay for power distribution - or just use the ACC lead to provide power for the relay, wire it up through the toggle switch, and ground the other side. Key off? Lights off. Key on? You can turn the lights on.

5-90

 

[nhrocker]

It's a good plan to stick with the 55w bulbs. I've got some of the 550's on my rig and they came with the 55's in them, they lasted for years. When I finally blew one I tried a 100w and it blew within 3 months. Yes, it was brighter, but I don't think it was enough of a difference to make it worth replacing them multiple times a year.