2016 Suburban LT Fog Lamps install with OEM switch

[Javaso]

Hooked mine up as described, and they work. The key being making sure you are using the correctly colored wire in the correct location. The only hiccup I currently have is that sometimes when you remote start the car, or simply unlock it, i.e. anything the makes the parking lamps flash... then theres a chance the fogs will come on. And in my case, Rigid SR-Q2's with a crazy bright spot beam. As a result, I may change the 611T to a positive output, and setup the relay for positive connection vs negative. Unless someone else has a quick fix.

I connected the fog lights wire to the brown cable of the harness coming out of the fuse box and the fog lights and running lights are on, even with disconecting the switch. Any ideas?

 

[Javaso]

Best suggestion I have is to pull out a multimeter and see where the break in the chain is. Start at the switch, verify that the you see ground there when you press it (or lose voltage). Then move on to the 611T and verify that it's turning on, then go under the hood, if you put a relay there, make sure it's getting the signal from the 611T. You should be able to trace the problem somewhere in all that.

Verified the oem switch with voltmeter and not throwing any pulse. It doesn't fluctuate.

 

[OxF16]

so similar to my situation, yet different... hmmm. check voltage pulse out of 611T?

 

[nilleo]

I think I misunderstood your original problem. Is your problem that the switch doesn't trigger the 611T or that the lights are always on?

 

[nilleo]

Hooked mine up as described, and they work. The key being making sure you are using the correctly colored wire in the correct location. The only hiccup I currently have is that sometimes when you remote start the car, or simply unlock it, i.e. anything the makes the parking lamps flash... then theres a chance the fogs will come on. And in my case, Rigid SR-Q2's with a crazy bright spot beam. As a result, I may change the 611T to a positive output, and setup the relay for positive connection vs negative. Unless someone else has a quick fix.

Did all the wiring and when we conected the fog lights wire to the brown, coming out of the fuse box under the hood, the running lights and fog lights turns on, even disconnecting the switch. Have verified all connections and don't know what is causing this. Need help.

I connected the fog lights wire to the brown cable of the harness coming out of the fuse box and the fog lights and running lights are on, even with disconecting the switch. Any ideas?

It sounds like you both have the same issue, and I suspect the root is catching the wrong brown wire coming out of the fuse box. Make sure that when you test that brown wire with your multimeter, it does NOT change 12V-0V or vice versa when you turn any of the lights on (parking, headlamp, etc.).

Also, take note of what color wire you're looking for! In my original post I mention that the wire you're looking for could be Brown or Brown/White depending on what you have at the BCM in X5, pin 10. If you have a Brown wire there, you're looking for a Brown wire under the hood, if you have a Brown/White wire there, you're looking for a Brown/White.

From here your plan of attack should be to confirm you have the same wire under the hood as you do at the BCM... an easy way to check would be to confirm the BCM side since you can visibly see the pin (see my original picture below). Unfortunately you can't test this wire very well since your truck isn't equipped with fog lights, so the BCM will never do anything with this wire other than supply a pull-up voltage, but you can count the pin location!

Once you confirmed that wire, turn ignition on and supply ground to that wire with the 611T or with some other source. Then go under the hood and test the wire you found under the hood and make sure it's testing the exact same way i.e. when you ground the inside wire, the outside wire should have 0V, otherwise it should have ~5-12V.

Lastly, make sure you're driving a relay with that underhood wire! I think I mentioned how to wire that relay in an earlier post, but in case I didn't it should look something like this...

85 - underhood brown or brown/white wire
86+87 - 12V constant source underhood mentioned in original post
30 - to fog lamp 12V+ input

 

[04ctd]

This needs to be a sticky.

can you PDF the schematics up as JPG's?

two questions:

Does the Intellibeam still work automatically (rumor is, it does not if the OEM fogs are on)
http://www.tahoeyukonforum.com/thre...low-beams-how-do-you-force-it-to-start.88867/

does the fog light indicator work on the dash? I would think not, since the BCM is not programmed for Fog lights.

request an update from anyone who bought the cheap eBay fog lights with plastic lenses, how are they holding up? scratched to death?

 

[nilleo]

This needs to be a sticky.

can you PDF the schematics up as JPG's?

Not sure what you mean by that, do you want a PDF or a JPG?

two questions:

Does the Intellibeam still work automatically (rumor is, it does not if the OEM fogs are on)
http://www.tahoeyukonforum.com/thre...low-beams-how-do-you-force-it-to-start.88867/

This is my parents' truck so I'm not sure it has Intellibeam, is it equipped on all trims? Regardless, the way I explain to wire everything ensures that the fog lamps work anytime the parking lights are on, so yes, they would still work with Intellibeam on/off since the fog lamps would be dependent on only the state of the parking lamps and the fog lamp request switch. If this is a feature on all trims, I'll verify that it all works as I'm claiming the next time I see the truck.

does the fog light indicator work on the dash? I would think not, since the BCM is not programmed for Fog lights.

That's correct, it does not work since the BCM is not programmed for fog lamps. As I mentioned in an earlier post, there's likely a CAN string that will request the indicator to come on in the cluster, even if it's just a message that's used for diagnosing the cluster modes, but that would take anywhere from a few hours to days to find--and I'm a full time student with access to the truck only on holiday--let's be real, if I'm on holiday away from school, I'm going to be doing nothing ha!

request an update from anyone who bought the cheap eBay fog lights with plastic lenses, how are they holding up? scratched to death?

I might visit the parents over the weekend, if I do, I'll try and snap some pictures of how they're holding up. I'm certain they've put well over 10k miles on them already on LONG road trips.

 

[04ctd]

do you want a PDF or a JPG?

assume you can't attach a PDF in the forums, and would have to make it a JPG to have it show up, but IDK.

good work, this a GOOD thread, ought to be a Sticky @NathanJax

 

[nilleo]

Are you asking for the original GM schematics? You can find them free, officially, at https://www.gmupfitter.com/pages/body-builder-manuals

 

[04ctd]

Thanks, I downloaded the schematics and looked them over, here are some notes, be advised, all this refers to a 2016 vehicle/schematic:

Front Fog Lamps (RPO T3U) and Rear Fog Lamps (RPO T79)
most info is shown on page 41, it is comprised of three circuits:
Circuit 192 - from Headlamp switch to BCM
Circuit 1317 - is from the BCM to control Fog Relay KR46
Circuit 2234 - +12v output to Fog Light bulbs.


RPO Description
T3U LAMP FRT FOG-FRT FOG
T79 LAMP-FOG, RR (T79 is the ReaR fog lamps, which are only European? canadian?)

here are the page numbers to find the connector picture/description/schematic:

X50A Fuse Block - Underhood X1 page 430
Pin Size Color Circuit Function Terminal Type ID Option
J3 0.5 BN/VT 2234 Front Fog Lamp Supply Voltage III T3U

X50A Fuse Block - Underhood X3 page 434
Pin Size Color Circuit Function Terminal Type ID Option
L5 0.5 BN/WH 1317 Fog Lamp Relay Control I T3U

K9 Body Control Module X1 page 727
Pin Size Color Circuit Function Terminal Type ID Option
4 0.5 RD/BN 2240 Battery Positive Voltage
15 0.35 D-BU/GY 192 Front Fog Lamp Switch Signal T3U
22 0.35 L-GN/GY 13 Headlamp Switch Park Lamp Signal

K9 Body Control Module X5 page 735
Pin Size Color Circuit Function Terminal Type ID Option
10 0.5 BN/WH BN 1317 Fog Lamp Relay Control T3U

S30 Headlamp Switch page 1001
Pin Size Color Circuit Function Terminal Type ID Option
10 0.35 D-BU/GY 192 Front Fog Lamp Switch Signal I T3U

X100 Forward Lamp Harness to Front Bumper Harness (X88 or Z88) page 1122
Pin Size Color Circuit Function Terminal Type ID Option
3 0.5 BN/VT 2234 Front Fog Lamp Supply T3U

 

[04ctd]

You did an awesome write up, the only issue I found was you used pin 6 (rear fog lights) instead of pin 10 (front fog lights) coming out of the headlamp switch, which should not matter.

LMK if this helps anyone, or muddies the waters, i can delete it if it just confuses ppl more:


611T wiring
Black – to BCM brown connector, Blue - pin 22
(wire color L-GN/GY, in circuit 13, which is the Headlamp Switch Park Lamp Signal, see page 728)

Green – to headlamp switch, Blue/Gray – pin 10
(wire color D-BU/GY, in circuit 192, which is the Front Fog Lamp Switch Signal, see page 41 & 42)

Red – to BCM brown connector, Red/White – pin 4
(wire color RD/BN, which is Battery Positive Voltage, page 727)

Yellow – to BCM brown connector, Blue – pin 22
(same as above, Park lamp to enable the module only when park lights are on, see page 42)

Brown – to BCM brown connector, Brown – pin 10
(wire color BN/WH (or BN) in circuit 1317, so this controls the OEM relay, see page 41)


611T wiring explained
The module is “active” when the Black wire is at ground and the Red wire is at 12V+. I wired it up so that it only has ground when the parking lamps are active so that the fog lamps can only come on when the parking lamps are on, and turn off when the parking lamps turn off.


Black wire is ground (this ground is switched by the Park lamps via the headlight switch as shown on page 42).
Red wire is 12V+ (battery)
Green wire (input) receives the momentary pulse from the headlamp switch to control the 611T
Yellow wire (grounded by park light) is looped to the Black wire so that it only has a ground input when the parking lamps are on as well.
Brown wire (output) is what will trigger the aftermarket fog lamp relay on/off with each press of the fog lamp switch


Page 42 has a schematic which shows the ground thru the switch and up to Pin 22 of the BCM.

 

[nilleo]

Yea, I grabbed the rear activation over the front due to convenience. Electrically, they tested the same and I knew it would function just the same.

 

[ChevyGirl111]

Yea, I grabbed the rear activation over the front due to convenience. Electrically, they tested the same and I knew it would function just the same.

Can you tell me if you had to cut a hole in the dash at all? I got my fog lights today came with the wires and everything but did you tap into the lights or did you actually install a switch to turn them off and on?

 

[nilleo]

Can you tell me if you had to cut a hole in the dash at all? I got my fog lights today came with the wires and everything but did you tap into the lights or did you actually install a switch to turn them off and on?

Nope, didn't need to cut into the dash at all. I removed the original light switch that our Suburban was equipped with and replaced it with a light switch from another GM truck that had factory fog lamps in order to add the fog lamp on/off switch to the truck.

Here's the switch I used (referenced in the original post from this thread):
GM headlamp switch w/fog part# 22752195

Let me know if you have any other questions!

 

[ChevyGirl111]

I don't have that switch, what should I do?

 

[Tahoe14]

Use the part # listed and buy one from your dealer or the internet.

 

[ChevyGirl111]

Thank you for your help! They are being installed Saturday

 

[ChevyGirl111]

Nope, didn't need to cut into the dash at all. I removed the original light switch that our Suburban was equipped with and replaced it with a light switch from another GM truck that had factory fog lamps in order to add the fog lamp on/off switch to the truck.

Here's the switch I used (referenced in the original post from this thread):
GM headlamp switch w/fog part# 22752195

Let me know if you have any other questions!

Can you tell me what bulbs the fog lights take? I have tried searching but not really getting straight forward answers. Appreciate the help!

 

[ChevyGirl111]

Got the fog lights installed with the chrome toppers they look so good! Matched the headlights and fogs hid's

 

[beachcomber]

This is such a great thread, as I just got my fog lights in the mail. However, as good as this write up is, is there an easier way if one doesn't want to use the OEM headlight switch? I'm thinking it'll suit my needs jut fine if I use an aftermarket toggle switch. Does anyone have a link that would show how to wire our fog lights just to a basic switch? For my skill level, even that'll be a stretch but seems more plausible for me to do.