question 94 altima poblem!

[240altima26]

Hey thank u for reading and hope someone can answer. I have a 94 altima and the coolant gauge and check engine light and clock dont work. I was wondering if they all used one plug under dash. I think someone may have unhooked so the cel would not be on. also there is a black plug under passinger side behind radio that is not hooked up. Thinking that might be the problem I hooked it up and it made a noise like a cd player stuck loading itself. The only diff. I noticed was it reset my radio. I have searched and even got a service manual. Nothing gives me a clear answer. Any help will be appriciated. Thank you!

[MaximA32]

Have you checked all the fuses in the panel? All fuses and such under the hood?

[240altima26]

Yeah i have checked those the only thing I found was that the power mirror fuse was missing. I dont think that would have anything to do with it but I am putting a new one in tomorrow. Everything else seems to be fine. I am lost with it. Thank you for your input