Blazer oem fog light switch

[JoseyMichael]

How do I make a momentary switch work like a continuous-current switch? I put on after market fog lights, I wired them to a relay to an on/off rocker switch. But I didnt like it, I want the factory look inside. So I went and got the oem fog light dash switch for it. How do I wire the relay to the factory 4 pin/wire factory momentary fog light dash switch? I want it so fog lights only on/off when I use the oem switch. I dont want them to come with low beam lights or parking lights or any that mess. I dont need them on all the time, it's on a 2001 S10 Blazer Z-R2.. Any help would be great!

[old_master]

The original fog lamp switch wiring goes to the BCM, (Body Control Module). The BCM supplies the ground for the fog lamp relay. The logic is done in the BCM, and the park lamps must be on before the BCM will latch the fog lamp relay. The OEM momentary switch and aftermarket relay that you're using will not latch the relay continuously. You'll need a SPST (single pole single throw) latching switch, either rocker, push button or toggle, to keep your relay latched.

[JoseyMichael]

Thank you for your reply! Sure glad there are guys around like you people to help guys like me.
I replaced and hooked up the OEM light switch that has the momentary button fog light switch with it in the dash. My Blazer didnt come with that OEM fog light switch, but the factory wiring was there to plug it into the OEM fog light switch that i got at the junk yard. Do you or any one know where is the wiring at-where is the rest of the factory fog light wiring at to hook up to my after market fog lights? Do I tap into-wire it to the parking lights wiring or headlight wiring? Right now I have it wired to battery, relay switch i put in and to on/off rocker switch then to a fuse and fuse box. Can I disregard all that I hooked up and wire my after market fog lights to the factory fog light wiring where ever that is? Not sure how and where now to wire this. Thanks for any help on this.

[old_master]

Not sure if the wire harness is the same, (with or without fog lights) out by the bumper. It might be a different harness if the vehicle was not equipped with fog lights. Check the harness behind the bumper: each fog light has a connector with two wires in it, purple is the feed and black is ground. There is a spot in the underhood fuse panel for the fog lamp relay, make sure it has four terminals in it. The electrical connector at the fog lamp switch should also have the purple wire and it runs directly to the fog lamp relay in the underhood fuse panel. The wire is used to illuminate the fog lamp switch when they are on, it does not activate the fog lamps.

[JoseyMichael]

Hi, thank you for your time for answering. The fog light relay in the fuse box under the hood is there, 85, 86, 87 & 30. I pulled out each head light and didnt see any fog light harness or plug in's for the fog lights. Didnt really see any thing behind the bumper. I did see 2 wires together, a black & pink wire that run with the head light wiring harness, then they take a detour behind the headlight and go up to the top of the passenger fender and they run into a plug in and then they go to the firewall? Not sure what those 2 wires are for? Do you or any one know how to wire the fog lights the way it is wired from the factory? I have the OEM fog light switch in the dash, the plug in wires were there for it to plug it into the momentary fog light switch. The relay for the fog lights is there in the fuse box, just missing plug in harness to fog lights? and I don't know how that is wired, how to wire that. Anyone?

[old_master]

If the OEM wires are there, they'll be within a few inches of where the OEM fog lights mount.

[JoseyMichael]

The factory wires are not there to plug into the fog lights. If they were there, the 2 wires from each fog light hook up go where? Back to the relay in the fuse box? Or do they tie into the low beam lights? I was trying to wire my after market fog light so the work with the OEM fog light switch in the dash. Perhaps this isnt possible...

[old_master]

The black wire at each fog light goes to chassis ground and the purple wire runs from the relay to each fog light. You can run one wire from the relay to one of the fog lights and a jumper from one fog light to the other and they should work.

[JoseyMichael]

Thank you!!!

[JoseyMichael]

Hi, after further review, I did locate a black ribbed 2 prong plug in wire behind the grill towards the bottom just hanging there. The wires to it are Black & Green, they do run with the headlight wiring. I wasnt really able to find the plug in wire for the other side-driver side. My questions are, does anyone think that is the plug in for the fog light? are there suppose to be plug ins for each side? If it is the plug in for the fog light, can I wire both fog lights to that one plug in-will it still work like factory? Thanks..

[old_master]

The wiring schematic on yours says purple and black. Not sure what green and black are for but they're not for the fog lights. It might be for an ambient temp sensor or some other option that your vehicle doesn't have. Also, if the harness has the fog lamp wiring, both connectors would be there.

[JoseyMichael]

OK, Thank you for your knowledge on this, I really appreciate it.

[tinstar]

I know this is an old thread.

2000 Chevy Blazer LT 4wd
It did not come with factory fog lights, but the dash switch plug is there.
The fuse box fog lamp relay and fuse is there and both are powered.

I had the grill out today looking for the socket plugs, but no luck.
Like in a earlier thread, I also found a unused plug.
Green w/white stripe & Black wires.
It is not for the temp sensor. It’s plugged in and working fine.

I looked for any Purple/Black fog light wires with no luck?

Anyone have any idea if the connectors are hidden somewhere?

Any Current info would be great.

[tinstar]

Disregard
Found out they aren’t hidden.
It’s a regular wiring harness from the fuse block.

There are two different ones.
One headlight harness with fog light connectors
One headlight harness without.
That explains why wiring is complete TO the fuse box.

The unused plug I found is for the GM Home-link system, which my blazer does not have.

The headlight/fog light harness is GM #12159160 and still available.
It’s very expensive. $500+

Anyway
Problem solved.
Bought used GM harness on eBay.

[Blue Bowtie]

I discovered a similar thing on my '03 S10. The UEC seems to be the same whether the factory option is installed or not, with the fuses and relays present. I built my own harness after determining the factory harness was inadequate for operating higher power driving lights. The factory relay is only rated for 16A (Omron) as well, which is also inadequate for 100W lamps.

I'm in the snow belt, where LEDs and the OEM type lamps and plastic lenses don't get hot enough to stay clear.