Gen 1 - Speedometer Calibration Box HELP (yellow Box)

[Scottst]

Happy holidays all!
I have a gen 1 that I installed 3:55 gears in and now I’d like the speedometer to read right.
I have a yellow box and I have done the typical googling to find some exact instructions for a gen 1 and so far have not had any luck.
I’ve found lots of references to it. But no real instructions or answers.
It seems simple enough….. box needs power / ground and VSS signal in / out.
From my research I see that, on the VIC -
Pin 24 (white w/orange) is the input from the VSS
Pin 25 (white w/tan) is the output for the speedometer
So I guess my questions are -
Where is the VIC / this plug where I find the above referenced pins?
And, are people modifiying the VSS signal in or the speedometer signal out?
I’d like some advice before I just start messing with wires so I can avoid messing this up…..
Thanks so much for your help!

 

[BoondocSaint]

Gen 2 Yellowbox calibrator

Hi The speedo on my 1999 GTS need to be calibrated due to bigger wheels and different gearing. I just got my yellow box and tried to install it without succes. I was following the instruction and those are the problems I run into: 1. In the harness leading to the black PCM connector, I was...

www.viperclub.org

speedometer calibration box instructions

I bought a bunch of Viper parts and was going through the boxes. I found this very detailed document and determined it was from Unitrax in California. I'm kind of assuming it is for a Yellow Box, but can't be certain. It's very detailed and I'm sure it will help someone in the future.

www.viperclub.org

Might find your answers in these threads.

 

[Scottst]

Gen 2 Yellowbox calibrator

Hi The speedo on my 1999 GTS need to be calibrated due to bigger wheels and different gearing. I just got my yellow box and tried to install it without succes. I was following the instruction and those are the problems I run into: 1. In the harness leading to the black PCM connector, I was...

www.viperclub.org

speedometer calibration box instructions

I bought a bunch of Viper parts and was going through the boxes. I found this very detailed document and determined it was from Unitrax in California. I'm kind of assuming it is for a Yellow Box, but can't be certain. It's very detailed and I'm sure it will help someone in the future.

www.viperclub.org

Might find your answers in these threads.

I’ve been thru both of those threads and did not find the answers I seek……
Thank you tho

 

[Gibz]

The first link above has pictures. The connectors are behind the metal cover plate behind the drivers wheel.

You intercept the VSS signal.

 

[Shakazito]

I had similar issues when the Unitrax box in my Gen 2 died. I purchased a YB which seemed like it would be an easy install - never could get it to work. Instead, I sent the PCM to Dan Cragin at Specialty Performance do the speedo recalibration for 3:55 gears. He also adjusted the fuel and timing curve for the mods on my Viper, had the fan come on 10° cooler, and eliminated the skip-shift. All well worth the money. Maybe this would be an option for you.

 

[Scottst]

I had similar issues when the Unitrax box in my Gen 2 died. I purchased a YB which seemed like it would be an easy install - never could get it to work. Instead, I sent the PCM to Dan Cragin at Specialty Performance do the speedo recalibration for 3:55 gears. He also adjusted the fuel and timing curve for the mods on my Viper, had the fan come on 10° cooler, and eliminated the skip-shift. All well worth the money. Maybe this would be an option for you.

I wish it could be done thru the PCM….. It seems like the gen 1 cars are a bit different.
I’ve sent the PCM to Dan and he’s done a tune and some things but on the gen 1 he said he can’t program it for gear changes like the other cars….