Three prong to four prong fog lamp switch

sblanck71

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Original poster
Joined
May 1, 2022
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Location
Texas
Greetings,

Previous owner wired in fog lamps using relay and wiring to battery.
They didnt use a switch that replaces the blank below the HVAC controls.
I removed the switch and its three prong. I purchased the switch that fits in the blank but its four prong.
I have positive from battery, positive from lamps and negative from battery. Do I add a wire from the negative on the relay and run it inside to the fourth prong?
Base model X without the OEM harness so I would like to avoid going that route and rewiring the entire thing.

I am thinking I just need to run a negative from the 4th prong to a ground source?


Thanks
 
If I'm understanding this correctly, it sounds like you need a dash lights wire feed.
 
Greetings,

Previous owner wired in fog lamps using relay and wiring to battery.
They didnt use a switch that replaces the blank below the HVAC controls.
I removed the switch and its three prong. I purchased the switch that fits in the blank but its four prong.
I have positive from battery, positive from lamps and negative from battery. Do I add a wire from the negative on the relay and run it inside to the fourth prong?
Base model X without the OEM harness so I would like to avoid going that route and rewiring the entire thing.

I am thinking I just need to run a negative from the 4th prong to a ground source?


Thanks

Did you buy a factory switch or this,it’s only 3

IMG_5143.webp
 
Post a picture of the wiring diagram which should be embossed on the switch. As mentioned, it could be for backlighting.
 
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Well if that's the same switch you bought, it was advertised as a SPST but in the video he is wiring it as if it were a DPST. You don't need to run a ground wire from that extra terminal to your relay or to your fog lights because those are already grounded, so ignore that terminal. The only ground you need is the first one for the pilot light.
 
Well if that's the same switch you bought, it was advertised as a SPST but in the video he is wiring it as if it were a DPST. You don't need to run a ground wire from that extra terminal to your relay or to your fog lights because those are already grounded, so ignore that terminal. The only ground you need is the first one for the pilot light.

That is the conclusion I came to. Thank you