LED Light Bar Wiring...

[mwm695]

So today, I finished mounting my 21" LED light bar in the lower grill, but I'm not 100% sure on what to do for the wiring (I'll post a write up once the wiring is done).

Currently, I have the "Dealer Installed" square Hella's on there, and they're wired so that when the switch is on, and the low beams are on, the fog lights are on; when the high beams come on, they turn off. (Does anyone have the wiring diagram for these lights?) So as to not murder my newly installed alternator, I would like to only be able to have my 120w Light bar be on when the 110w fog lights are off (i.e. when the switch is off OR the high beams are on).

I bought a cheap wiring harness off Amazon (mostly just for the actual wires and connectors) that came with a 40amp 4 pin relay (most likely SPST). Any idea on how to wire the new relay so that the above happens?

My father is an industrial electrician (a busy one at that, hence why I'm not asking him), so if I'm really confused on something, I'll just ask him lol. :bravo:

Thanks!

 

[csp]

Trigger the relay with the high beam power feed.

Personally I'd want to be able to run the LED light with the low beams on and would just pay attention and keep the fogs off with the LED powered up.

Do you typically have the fogs on?

 

[Unner]

Is this actually something to worry about? Will running the fogs and a light bar stress the stock electrical system too much?

 

[mwm695]

Trigger the relay with the high beam power feed.

Personally I'd want to be able to run the LED light with the low beams on and would just pay attention and keep the fogs off with the LED powered up.

Do you typically have the fogs on?

Sorry, I should have been more specific in my original post.

Just to be clear, when the fog lights are on, the light bar should not be on. When the fog lights are off (i.e fog light switch off in low beams, or fog light switch on or off in high beams) the light bar CAN be on, if the light bar switch is on.

And yes, I typically have the Fog Lights on with headlights.

Is this actually something to worry about? Will running the fogs and a light bar stress the stock electrical system too much?

Yes and no. When at idle, the alternator creates (if I remember correctly), about 35 Amps, and with all the other lights/fans/radio/etc, the total power is 420w is nearly gone. It's just the engineer in me that wants to protect the system.

 

[csp]

Sorry, I should have been more specific in my original post.

Just to be clear, when the fog lights are on, the light bar should not be on. When the fog lights are off (i.e fog light switch off in low beams, or fog light switch on or off in high beams) the light bar CAN be on, if the light bar switch is on.

I understood that. Unless you use multiple relays and add diodes there's no easy way to have both.

Just turn the foglights off.

 

[theriddler]

So today, I finished mounting my 21" LED light bar in the lower grill, but I'm not 100% sure on what to do for the wiring (I'll post a write up once the wiring is done).

Currently, I have the "Dealer Installed" square Hella's on there, and they're wired so that when the switch is on, and the low beams are on, the fog lights are on; when the high beams come on, they turn off. (Does anyone have the wiring diagram for these lights?) So as to not murder my newly installed alternator, I would like to only be able to have my 120w Light bar be on when the 110w fog lights are off (i.e. when the switch is off OR the high beams are on).

I bought a cheap wiring harness off Amazon (mostly just for the actual wires and connectors) that came with a 40amp 4 pin relay (most likely SPST). Any idea on how to wire the new relay so that the above happens?

My father is an industrial electrician (a busy one at that, hence why I'm not asking him), so if I'm really confused on something, I'll just ask him lol. :bravo:

Thanks!

Ask your father if you're not 100% comfortable with this, he should know exactly what to do. If you have the new harness it should be easy, you do have to find which wire going to the headlights is the high beam and tap into that circuit. You don't have to cut the wire if you don't want, you will have to strip some of the insulation off and solder or crimp a wire on to get that power to your relay. The relay is going to transfer the power from the battery to your new lights, the high beam headlight wire will only "pull in" the relay and allow the current to flow....and when the high beams are off the relay returns to it's original state (normally open in this case).

Post a link to your Amazon relay so we can see what we're working with