Can I run all 4 lights off one relay harness or do I need to use one relay harness per 2 lights as they come? Just trying to reduce wiring if at all possible on my install. Thanks...

 

You could do it if the wire gauge and the relay will handle the current.

To get the amp rating of your Hellas, divide the wattage by the voltage.

55Watts/12 volts = 4.58 amps. That would be for a single lamp.

Multiply by four and you would be drawing more than 18 amps.

Here is a link to a wire gauge current limit chart.

http://www.powerstream.com/Wire_Size.htm

You should be able to get an answer to your question from that.

Dave

 

Thats a helpful chart but should I be looking at "Maximum amp rating for chassis wiring" or "Maximum amp rating for power transmission"?

 

The text above the chart has some explanation. I would go with the chassis wiring chart, as that is really what you are using the wire for. It sure doesn't hurt to make your wiring and your relay oversized to be sure you won't have any problems.

Also, be sure to put a fuse in your lighting circuit, that will handle a few amps more than your circuit's current draw.

Here is an explanation of how to size a fuse.

http://www.oznium.com/forum/topic15761

Dave

 

Wired everything up. Ended up using both relays for caution and to allow me the option of using higher wattage bulbs down the road if I want to. But now they still won't fire. For as many Hella 500 install threads as there are on this forum I can't find a single one with detailed instructions. I wanted to wire the lights to work when the high beams get switched on. I wired everything without using a switch in the cabin for an independent control. Is that causing a problem for some reason? Also, which bloody wire is the high beam hot lead on the headlight harness?!?! Only thread I could find mentioning it says the Yellow/Blue wire but the only wire with those two colors I would call Blue/Yellow as the main color is Blue with a seemingly yellow stripe. If anybody can help I would be super thankful...

 

The Hella instructions tells you to run your wire directly from the high beam thru their switch to the relay. Eliminating the switch shouldn't matter other than preventing you from turning off the driving lights. Unfortunately, I can't remember which wire I connected to at the headlight. I just used a voltage meter to determine which wire was hot ONLY when the high beams were on. It really wasn't necessary to use both relays; my Hella relay is rated for 40 amps (more than enough for 4 lights even with higher wattage bulbs). You can troubleshoot your wiring by connecting the wire meant for your high beams to any 12v source and the relays should energize and turn on your lights. The Hella wiring diagram is pretty straightforward. Follow it and you should get lights. Good luck.

 

Thanks Dave. I actually got unlazy right after I posted and busted out my multimeter. found the right wire on the headlight harness. Everything works great now. I did the math and realized I could use one harness but opted to use 2 because it's not really any additional wiring and I was considering going to 100w bulbs in the future. I hate wiring so I'm glad that project is over. Thanks for the help NAM.

 

Glad you got it sorted out. Four 100w bulbs should really put out some extra light.