Albizo66

so just 20 minutes ago i was on my way to my girlfriend's house, and my speedometer and stock tach decide to stick on me...now, it is very cold here in jersey tonight, and i have a bypassed heatercore, so no heat or defrost....

but the two needles jumped, and then just stuck there, so i used my Autometer tach for reference. my tach started to work as it "warmed up" but the speedmoter stayed up at 40 and would only come down in leaps as i was comnig to a stop...

this has never happened before, what could be causing it? is it the cold weather? how do i fix it? thanks guys