hey
i have a1994 silverado ext cab 4x4 350 and i bought it a month ago and there has always been a humming sound coming from the bottom of dash in the middle like next to the 4x4 can hear it clear as day with no radio and windows up in cab not outside of cab i was looking up online some people saw my flew plate could be cracked so i talked to a mechanic he said if it was cracked id hear something like a tin tick but he didnt kno what was making nosie in my truck i cannot seem to find the spot were it is coming from....tranny in it is a new used unknown miles but shifts perfect havent had any problems with that almost sounds like the fan for the heat but its not im really confused and was wondering if anyone could help me out
thank you!