How do I test an elec. speedo?

[niceolddart]

I have a 90 Ramcharger I'm parting out & have the instrument cluster out along with the complete wiring harness & VSS from the transfer case. Does anyone know how to check the operation of these electronic speedos without any damage. It's in very nice condition & don't want to ruin it. TIA

 

[MILO]

Hook it to the trucks speed sensor

 

[niceolddart]

Can I do this without the ECM hooked up, or other accessories plugged in? I removed the whole wiring harness, front to back, under dash etc. keeping it in good condition in case someone is looking for one.

 

[MILO]

Here is a video that will help

 

[niceolddart]

Here is a video that will help

Thanks MILO, that helps A LOT. I guess I should have checked YouTube first huh?