Wiring a shift light

[JT ZR-Won]

I had a small auto meter shift light in my previous '90 ZR-1. When I sold it I removed it and it has been sitting in a box for years. I just came across it and would love to wire it my (new to me) '90 ZR-1. The problem is I absolutely cannot remember how I did it. I believe one of my friends helped me do it originally.

Just being upfront, I am a complete electric wiring buffoon, lol. There are 3 wires coming out of the auto meter box.... black, red, and green. Where is the best place to tap into for ground, power, and RPM's?

Thanks in advance and I'm sure I'll have more questions.

Jay

[AndrewL]

I'm glad you posted this. I just dug my old Harlan shift light out of storage and would like to install it for old times sake and was wondering where people were getting their tach signal from.
For positive power, if you want to keep tapping into other wires to a minimum, you can buy an add a circuit that will let you piggyback off an existing fuse so you can draw power via an existing circuit for power

For the other stuff, I'll defer to the guys who've actually done this on their Z.

[XfireZ51]

You can use the ignition diag connector to hook up your shift light.

[JT ZR-Won]

I'm glad you posted this. I just dug my old Harlan shift light out of storage and would like to install it for old times sake and was wondering where people were getting their tach signal from.
For positive power, if you want to keep tapping into other wires to a minimum, you can buy an add a circuit that will let you piggyback off an existing fuse so you can draw power via an existing circuit for power

For the other stuff, I'll defer to the guys who've actually done this on their Z.

That is pretty cool, I'll have to look into this. I did find some really old posts about this subject that had links with instructions but the links were all taken down probably a long time ago.

[A26B]

Here is a pretty good link for RPM signal.

http://www.zr1.net/forum/showthread.php?t=8652&highlight=shift

[JT ZR-Won]

Here is a pretty good link for RPM signal.

http://www.zr1.net/forum/showthread.php?t=8652&highlight=shift

Great info thanks!

[AndrewL]

Here is a pretty good link for RPM signal.

http://www.zr1.net/forum/showthread.php?t=8652&highlight=shift


That's a great link, thanks for sharing! :cheers:

[JT ZR-Won]

Just curious if anyone has any photos of where they tapped into the tach wire? This might help me tremendously.
I did manage to see a mob of wires coming in from the firewall but still not 100% on which one to start splicing into. Boy, forgot how tight it is in that footwell!

[chris90]

I think on my corvette, a former owner
made the change. What do you think of the photos?

[JT ZR-Won]

Looks like the previous owner did a pretty clean install. Pretty cool

[chris90]

Looks like the previous owner did a pretty clean install. Pretty cool

I'll restart it, but I don't have the wiring anymore and I don't know what to do yet.

[JT ZR-Won]

Ok, so this small project got put on hold for a while but it is now finished. I wanted to update this thread with some photos because when it comes to this stuff, I'm much more of a visual person and this might help someone else out.

REMINDER: This install is on a 1990 and I'm not certain if it is the same on other years.

I located the C100 Terminal in the footwell. There was no need for me to feed any wires through the firewall. I took the best photos I could as you're pretty much twisted up like a pretzel at this point. It is directly to the left of the clutch pedal.

I located the white tach wire that leads to the instrument cluster. This was located in the E1 slot (I believe it was E1... it is the only white wire I saw) on my '90. The slots are actually labeled, but they are labeled super tiny but I could see them with a flash light. I spliced into the white tach wire and connected the green tach wire from my auto meter.

I then grounded the shift light underneath the instrument cluster right next to the radio. I don't use the cigarette lighter so I ran the shift light power to it. The autometer control module just sits inside the center console. It came with double sided tape but it really cannot move. Everything works perfectly and I hope this helps someone else.

Cheers! :cheers:

Jay

[JT ZR-Won]

I chose to mount this above the dash so it can be seen. It is a pretty small light and looks pretty cool.

[XfireZ51]

No splicing necessary if u use the diag connector for the Ignition Module by the firewall.

[aafc]

Interesting , I had a shift light that mounted to my autometer tach. Then I
removed the 6-speed transmission back in 2009.
Well I do not need a shift lite as the transmission controller is set to shift at what ever I want. Setting the controller to 7000 rpm shift at the races the car would loose power at the shift point. After two runs I realized that I was hitting
the fuel cutoff. Dummy , so I set shift at WOT to 6800 rpm and no more shutting down at full throttle runs. Just to show that you should pay attention
to what you are during . You know measure twice ,cut once.
JOHN

[XfireZ51]

Interesting , I had a shift light that mounted to my autometer tach. Then I
removed the 6-speed transmission back in 2009.
Well I do not need a shift lite as the transmission controller is set to shift at what ever I want. Setting the controller to 7000 rpm shift at the races the car would loose power at the shift point. After two runs I realized that I was hitting
the fuel cutoff. Dummy , so I set shift at WOT to 6800 rpm and no more shutting down at full throttle runs. Just to show that you should pay attention
to what you are during . You know measure twice ,cut once.
JOHN

Fuel cutoff/ turn on can be modified via calibration.

[aafc]

The fuel cut off limit has been fixed to higher limit. This is not something you
could do at the drag strip unless you have right the equipment.
This happened about 4-5 years ago. IT seems that the tune works good by
auto shift at 6800 rpm having run consist mid 11's all day long.
John