Shift light installation signal wire?

2023ZL1RapidBlue · 09-17-2025, 08:05 AM

Hey there folks.

Currently, I have a P3 Gauge plugged into the OBD port.
I want a shift light because the HUD is just not bright enough for me and the P3 gauge flashing feature isn't bright either. I bought an OBD Holley Sniper Shift light with a splitter.

Turns out that even with P3 gauge set to Low Priority mode, the Holley shift light will error out, so both devices won't talk on the same port. I was kind of expecting that. However. It can vary from device to device. I'm just ready to retire the OBD option with splitter.

So, I want to install a standalone shift light. My searches have not conclusively gotten me to a definite answer where to grab the signal wire from. I've read people having issues grabbing the signal wire right off the 1st coil. I also read people having issues with the GMR pickup.

So, where the heck do you connect the engine speed signal wire to on a 2023 ZL1?

2023ZL1RapidBlue · 09-25-2025, 10:32 PM

I guess no one has done this, huh.

arpad_m · 09-25-2025, 11:43 PM

There are custom steering wheels that come with shift lights, maybe someone who installed one of those could help...? Mine that came from Carbon Addons was offered with an LED shift light display as an option, but I ordered it without one, this ain't a Ferrari

and I didn't want to mess with an extra plug or wiretap.

2023ZL1RapidBlue · 09-27-2025, 09:33 AM

Quote:

Originally Posted by arpad_m

There are custom steering wheels that come with shift lights, maybe someone who installed one of those could help...? Mine that came from Carbon Addons was offered with an LED shift light display as an option, but I ordered it without one, this ain't a Ferrari

and I didn't want to mess with an extra plug or wiretap.

Thanks for the suggestion. I did look at those and they're nice.
But, then, there is the fact of paying $200 for a shift light or $1700 for a shift light

, although, they're nice.

Are the lights pretty visible during the day?

RobZL1 · 09-27-2025, 09:52 AM

For what it's worth, I installed a Raptor shift light on my gen 5 ZL1 and I used the #1 coil wire as the signal. Worked great. On the 6th gen, I believe you want pin C, and it should be a blue wire, I think.

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2023ZL1RapidBlue · 09-27-2025, 10:17 AM

Quote:

Originally Posted by RobZL1

For what it's worth, I installed a Raptor shift light on my gen 5 ZL1 and I used the #1 coil wire as the signal. Worked great. On the 6th gen, I believe you want pin C, and it should be a blue wire, I think.

Attachment 1168572

Attachment 1168573

I was looking at the Raptor shift lights but couldn't find a yellow one so I'm purchasing a Holley Sniper yellow light.

Cool blue light on your setup though. Thanks for the photos and the info the pinout. We'll see how it goes.

WiggyB · 10-02-2025, 07:40 AM

A friend suggested this to me since I have my P3 gauge plugged in to the port. When I log as you know having to unplug the gauge to hook up the hp tuners dongle is just a nuisance but no reason for me to get one.
https://www.amazon.com/ZIMISI-OBDII-...9405030&sr=8-7

2023ZL1RapidBlue · 10-11-2025, 01:54 AM

Quote:

Originally Posted by WiggyB

A friend suggested this to me since I have my P3 gauge plugged in to the port. When I log as you know having to unplug the gauge to hook up the hp tuners dongle is just a nuisance but no reason for me to get one.
https://www.amazon.com/ZIMISI-OBDII-...9405030&sr=8-7

Thanks for the suggestion. However, the Holley Sniper Shift light does not function on a shared OBD as I came to learn. Even when I put the P3 gauge into low priority mode, it still would not function so I returned it.
I went with a hardwired light. Haven't installed it yet.

2023ZL1RapidBlue · 12-04-2025, 10:53 PM

Quote:

Originally Posted by RobZL1

For what it's worth, I installed a Raptor shift light on my gen 5 ZL1 and I used the #1 coil wire as the signal. Worked great. On the 6th gen, I believe you want pin C, and it should be a blue wire, I think.

Attachment 1168572

Attachment 1168573

Finally got to install my Holley Sniper Shift light.
Thanks for the tips on the pinouts. I did confirm that also with Raptor's shift light instructions. C wire was it! I had nowhere to tap for 12+ as there's no nearby fuse box. It's either under the hood or trunk, or tapping into an existing circuit. Well, I wired it all (+,-,signal) to the coil. I did use coil #7 as it's closest to the firewall, less wire to run. Works great!

09-25-2025, 11:43 PM	#3
arpad_m Drives: 2018 Camaro 2SS A8 Join Date: Jul 2017 Location: East Tennessee Posts: 13,150 View My Garage	There are custom steering wheels that come with shift lights, maybe someone who installed one of those could help...? Mine that came from Carbon Addons was offered with an LED shift light display as an option, but I ordered it without one, this ain't a Ferrari and I didn't want to mess with an extra plug or wiretap. __________________ 2018 Camaro 2SS — G7E MX0 NPP F55 IO6 735 rwhp \| 665 rwtq Magnuson TVS 2300 80mm pulley \| Kooks 1 7/8" LT headers \| JRE smooth idle terminator cam \| LT4 FS & injectors \| TSP forged pistons & rods JMS PowerMAX \| DSX flex fuel kit \| Roto-Fab CAI \| Soler 95mm LT5 TB \| 1LE wheels \| 1LE brakes \| BMR rear cradle lockout \| JRE custom tune 1100 - 1/30/18 \| 2000 - 1/31/18 3000 - 2/06/18 TPW 2/26/18 3400 - 2/19/18 \| 3800 - 2/26/18 4300 - 2/27/18 \| 4B00 - 3/01/18 4200 - 3/05/18 \| 4800 - 3/14/18 5000 - 3/16/18 \| 6000 - 3/19/18

09-27-2025, 09:52 AM	#5
RobZL1 fo'shizZL1 Drives: 2017 ZL1 Join Date: Aug 2017 Location: ATL Posts: 1,805	For what it's worth, I installed a Raptor shift light on my gen 5 ZL1 and I used the #1 coil wire as the signal. Worked great. On the 6th gen, I believe you want pin C, and it should be a blue wire, I think. __________________ 2017 ZL1 M6 Black \| Maggie 2650 // 103TB // Big Gulp // CSP LT's & Ultra Cats // BMR MM // BC Forged KL13 Mods being installed- oil pump, cam, ported heads, dual in-tank, Goliath and XDI, corn, etc., etc.

09-17-2025, 08:05 AM	#1
2023ZL1RapidBlue Drives: ZL1, S2000 Join Date: Mar 2023 Location: Connecticut Posts: 114	Shift light installation signal wire? Hey there folks. Currently, I have a P3 Gauge plugged into the OBD port. I want a shift light because the HUD is just not bright enough for me and the P3 gauge flashing feature isn't bright either. I bought an OBD Holley Sniper Shift light with a splitter. Turns out that even with P3 gauge set to Low Priority mode, the Holley shift light will error out, so both devices won't talk on the same port. I was kind of expecting that. However. It can vary from device to device. I'm just ready to retire the OBD option with splitter. So, I want to install a standalone shift light. My searches have not conclusively gotten me to a definite answer where to grab the signal wire from. I've read people having issues grabbing the signal wire right off the 1st coil. I also read people having issues with the GMR pickup. So, where the heck do you connect the engine speed signal wire to on a 2023 ZL1?

09-25-2025, 10:32 PM	#2
2023ZL1RapidBlue Drives: ZL1, S2000 Join Date: Mar 2023 Location: Connecticut Posts: 114	I guess no one has done this, huh.

10-02-2025, 07:40 AM	#7
WiggyB Drives: 2022 Camaro 2SS 1LE Join Date: Nov 2021 Location: NC Posts: 377	A friend suggested this to me since I have my P3 gauge plugged in to the port. When I log as you know having to unplug the gauge to hook up the hp tuners dongle is just a nuisance but no reason for me to get one. https://www.amazon.com/ZIMISI-OBDII-...9405030&sr=8-7 __________________ d1sc factory box w/ stage 2 intercooler, Lt4 fueling, JMS BAP, lt2 intake, kooks 1/78 longtube headers w/ h/f cats, alky meth kit, thpsi port injection

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