Fog light question

[Frankdm83]

I am putting factory 97+ fog lights on my MJ as part of its front end upgrade. The truck does not have a fog light switch on it. Would it be harmful the splice into the low beam power wire for the fog lights so they go out when the hi beams come on, or is there another way i should wire it?

[Pete M]

Your foglights should be on their own relay or you're likely to blow the fuse or burn out something.

But you can can certainly splice that relay's activation wire into the hi-beams if you so desire. Relays take very little power to switch. Although most cars today have fogs that turn off if you turn on the hi-beams.

[deziped]

Yes you can. And your low beams will go off when you switch to highs as you intend.. But as previously advised go through a relay.

[HOrnbrod]

I am putting factory 97+ fog lights on my MJ as part of its front end upgrade. The truck does not have a fog light switch on it. Would it be harmful the splice into the low beam power wire for the fog lights so they go out when the hi beams come on, or is there another way i should wire it?

 

ASSuME you are putting these on your 89? The wiring for the dash switch to the front connector should already be there. All you have to do is pick up a factory fog light bezel w. switch and plug it in. Here's an old post how I installed mine using the existing harness and adding a relay:

 

"Okay, I've done this using most of my factory wiring on my 1991. The dash fog light switch gets input power on pin B (the VIO/WHT wire on my 91) from the headlamp dimmer switch. This is to prevent the fog lights from coming on when the high beams are on. Cut this wire and splice a fused 12V source which comes on with the ignition. Pin C (the BRN/WHT wire) on the switch is the output which goes to the fog light relay. If you don't have factory fog lights, you won't have a fog light relay. You can pick the BRN/WHT wire up on pin #10 of the 10-pin connector located in the left front of the engine compartment. Use your meter to identify it when your turn your fog light switch ON; you'll have 12V. Run a new wire from pin #10 to the coil side of a new auxillary relay.

 

This will apply 12V to the relay coil to energise the relay. Of course you have to hook up the other pins of the aux relay too, which are normally pinned out like this:

 

Pin 86: 12V from fog light switch to the coil

Pin 85: Ground (other side of the coil)

Pin 87: 12V relay contact input, NO, (I picked up my 12V on pin 6 of the 10-pin connector above, same way the factory did it)

Pin 30: 12V relay contact (NC) output to your lights

 

By using the aux relay you protect your dash fog light switch since all the amp draw from the lights goes through the relay contacts. You can run at least two 100W halogen lights or more, depending on the amperage

rating of the aux relay you put in. Make sense?"