Alright so I removed the instrument cluster to get all my dash lights working and installed a new dimmer switched. Pretty sure I plugged everything back in correctly but now my temp gauge never leaves cold....anyone know how I can test this or know what plug on back of instrument cluster is for the temp gauge? Thanks for your help in advance! Btw I have a 67 plymouth belvedere

 

Your temp gauge will be a violet or purple colored wire. Sorry do not have wiring diagram of vehicle