Can someone tell me where specifically the white tach wire and green/white VSS wire goes? I believe they originate in the ECU on the Red 10 & 50 pinout locations respectively. Do they go into the DRAC modules within the gauge cluster? If so, where exactly? Any help you can provide on this would be appreciated! (Additional info: Engine is 2002 Corvette LS1, trans is 4L60E). Thank you!


DRAC modules (speedo on left, tach on right)

 

Has anyone wired a gauge cluster with an LS swap? ? Not even the Supreme Members?!

 

Planned to work on her this weekend...anyone have any insight here?

 

It's a white wire in engine bay, and with my Firebird it stays white all the way to the gauge pod. Wiring schematic for your car will tell you the color.

Never seen anybody splice in behind the gauges. People usually splice to the wire in the engine bay because the rest of wiring to gauge pod is already laid in the stock dash harness.

 

Thank you @QwkTrip I don’t have a stock harness. I’ve got a painless harness wired to the LS1. Thoughts now? That’s why I wanted to wire into the DRAC modules as I have easy access to them. For the white wire for example, the module has three solid white wires going to it. Do you happen to have a schematic of these two DRAC modules?

 

Sounds like what you really need is the pin identification in the connector since you can't trust wire colors any more. For example, with my Firebird it is terminal pin C1-1 of the brown connector. I know that because I can see it in the GM service manual, and they have a neat little picture of which one is C1-1.

Austin thirdgen might have schematics for your car. I'll let you do the digging, https://austinthirdgen.org/
If it's a Chilton's manual type schematic then good luck, I hate those. If it's a schematic from a GM service manual it will be easy as pie.

 

Well, there's another way to figure this out too. Look at the green screen on the back of your stock gauge cluster and go to the screw on the back of the tach for the tach signal. Follow that trace in the screen back to the connectors and that's the terminal you use.

I've done this before, it's easy as heck. There are multiple screws on the back of the tach and the one that DOES NOT share wire trace with any other device is the tach signal.

With my tach there are 4 screws, if I remember right. One is a ground and the trace goes to light bulbs and stuff like that. The other is B+ and that trace goes to other gauges too. One screw is just for mounting and has no trace to it. And the last screw is the actual tach signal and that trace goes back to connector without going to any other devices.

 

Thank you @QwkTrip ! I will certainly give that a try. Have a similar process for the VSS on the speedo side? And if you do happen to come across the DRAC module pin-out diagrams, please share. I do not have that or a Chiltons. Thank you!

 

Here is the stock layout for the gage harness connections.

 

Thank you @ShiftyCapone ! So would I be correct in connecting tach (wht) and the VSS (grn/wht) as shown here to #7 (wht) and #1 (brn) respectively? Thanks again!

 

Yes you are correct. I think the INFL light is a separate brown wire circuit than speed input. I'd have to study the above diagrams to see where they go from the cluster.

 

When in doubt follow the wire trace to the gauge. That will help you figure out which way the row of pinouts are oriented in the car.

Having a system of double checks is a good thing.

 

This is good advice. I did this with my cluster and learned a great deal.