There is no power to the diagnostic port. What can I look for as a possible solution?

Check the fuse that powers the DLC - diagnostic connector , this power's up their diagnostic machine . What year , make , model vehicle ? Maybe we could direct you to the fuse location .

As both the radio and ventilation motor packed up simultaneously, I suspect a common 12V positive feed, so if fuses ARE ok, then try unclip fuse box as far as possible to look for a burnt off / broken terminal. As you said p-locks & p-windows didn't work before, there might be loose connections hidden away under dashboard, behind console (center).
Happy hunting!! :)
Clive.

The initial thing that i see is your vehicle is too young to show that type os code.the two digit code 23 has not been used since 1995.It's an obd1 code.Your vehicle has obd2 class diagnostics on board.The code would be po171 or po172 for example. I would get a second opinion if i were you .Try running a few tanks of premium fuel. This can often wake up an o2 sensor by cleaning it up a bit.Hope this information helps,
Ken

any of the larger retail parts stores will scan the car for free. get the codes and get back to me we'll go from there.Please rate my fix? as i strive to be the best Thanks Ray

Starter solenoid most likely. Check the connections on the solenoid and the starter itself.

P0300 is a multiple cylinder misfire and is used by all OBD2 vehicles on the road in the USA that is 1996 and newer, P0301 is cylinder number 1..P0302 is # 2 and so on...that tune up may have been needed and parts and labor are expensive..you have a cylinder that is misfiring and the cause must be located..possible causes are intake manifold air leaks..secondary ignition problems..fuel injectors..plugged EGR system if it has one..failed head gasket..burned or cracked valves..I have seen some crazy stuff..you need a tech on that one not a mechanic.

Hi i took the jeep into the dealers they said the fault was a intercooler hose, have to wait for part could this have caused all that smoke vehicle still there so no diagnostic sheet yet to see the code

Take it to Autozone, they do free diagnostics. They can point you in the right direction.

hi i think ur  dashboard as failed, if the dashboard has failedn Then u have to get new part and needs configuring from dealers is around £500...
thank u rate me!!