akdoggie

I know that some of you have added fog lights and fog light harness. My question is how many of you used a 2 relay system and who used a single relay. Also post up your reason for using the one you did. Anyone who has a dual relay setup, I would like to see how you mounted them and where. Thanks

Morrillo

One relay is more than sufficient to get the job done. The only reason I would use dual relays is if I want multiple options with a single multi switch. For example I can use the first switch selection to activate relay 1 as a normal "on or off". Then the second relay I would wire it to turn ON when other components are turned ON or maybe wired to a automatic on sensor. For simplicity and so I don’t forget to turn "on or off" the fog lights I just wired the relay coil to the 12V of the headlights so the fog turn on and off as my headlights are on or off.

Another reason that comes to mind is that the relays and cables you have available are not capable of handling the current draw and you divide it in 2 circuits to have a safer capable wiring.

There might be other reasons but ATM I cant think of any other reasons.

Attached is a single relay wiring I made for my install

Matt's 95 Stang

Why not go with a simple, proven methoid and get a Starsky pre-maid wiring harness? Might be alittle pricey (I think I paid $180 for mine) but they are well worth it. Looks OEM and came with excellent directions for me to follow.

Matthew

akdoggie

Thanks. That is exactly what I was thinking. I couldn't comprehend a reason you would need 2 relays other than 2 different sets of lights or using the second to run the lights on high beams. The article I was reading stated that the dual relay harness was better for our years. That is why I was asking if anyone had the dual system and if they would post the picture of it.

I built mine with a single relay system. Works and looks like a factory install except the fuse holder sitting by the strut tower. Other than that it works perfectly, has high quality wire, terminals, heat shrink and pigtails installed. I used a Bosch relay and harness plug for my set up.

157dB

I used two relays but only one was high current Fog Light relay.
The other was a simple reed relay with the coil wired to the high
beams so the fogs would operate with the high beams regardless.
I mounted the relay(s) just in front of the PCM and wired them
into the fuse box with a tap-a fuse.

I also used a GT headlight switch so the fogs could be interlocked
to the ding ding headlight reminder...

akdoggie

That is exactly what I wanted to hear. Use the second relay for the high beams side. I couldn't think of another reason to have two relays other than running 1 wire to each bulb. That would make it easier to put in the higher wattage bulbs without overloading the single relay.

I appreciate the answer. Both of you have confirmed what I could not find anywhere on the net. I read a lot about the dual relays but never saw anyone who did it. Thanks

157dB

Higher wattage bulbs?
How much higher?
A 30Amp relay at 12VDC can
switch 360Watts safely.
Even more at 13.8VDC (414Watts).
The stockers are 42Watts @ 13.8VDC.
Thats 3.04 Amps each...
Get where I am going.
2 relays are OVERKILL and unneeded
unless you are running 10 PIAAs....

Remember...
volts times amps equals watts.
watts divided by volts gives you amps.

tx_zstang

I used 1 relay, in the underhood fuse box where a GT would have it's foglight relay, along with parts of the stock wiring along with adding other wiring that was missing; now, except for the SJB which is bypassed completely, the foglight wiring is all stockish, with a relay in the BEC and wired going out of it through the headlight harness to the fogs.

Siber Express

I know on my Explorer it had a 2 relay aftermarket harness that worked with the factory lights and switches, the second relay was never used because if you followed the directions it plugged into the High Beams turning off the fogs, not keeping them off.
I myself would run the power to turn on the 1 relay off of the marker lights so you do not need the headlamps on to use the fogs.

akdoggie

It must of been late when I wrote that original post. Let me start over. I already have the single relay system installed. I have for a couple years. I wasn't trying to buy or build a harness.

I made my own up using a Bosch relay and pigtail. Some wire, heat shrink, plastic loom and quality lamp connectors, a few minutes of soldering and you're done. My cost was under 37 for everything and you can't tell it from the Sharkey harness. It took me about a half hour, but saved me 60. I used the factory GT switch, so everything looks original, except the wire attaching to the battery stud post at the box under the hood.

What I was really wondering was, if anyone had the 2 relay systems and basically why? If so would they post a picture to see. I'd never run across using it that way. I figured if it had advantages that I could use, I'd build one.

Recently, on another site, they were talking about the dual relay wiring harnesses being so much better. One of the companies stated that they have the dual relay system available and it was better. Another one said they used the single 40 amp relay system that was better, and others had other ideas and options. They seemed like overkill to me. A simple harness with relay, using good quality parts and wire, would work fine.

I could only figure that they used it for when the high beams were on, otherwise why have 2 relays. I considered that maybe the second was for an additional set of lights, but that could of been done by going off the original relay.

What 157dB said about the relay being able to carry the load, was absolutely right. It can take quite a load on the single 30 amp relay. That's why I questioned the dual relays. Thanks guys.