I bought the electric heater from Big Lots it is in my 7 year old grand daughters room, I need help fast, It comes on and the fireplace it on it blows out cold air only. I bought it 2 months ago.

Since it's 25 years old, I wouldn't call it a lemon, but I'm sure that there are issues. My guess would be rodents possibly made it there home for a bit and snacked on the wiring. Putting power to it has caused some short circuits that now need repaired.

Your post is very convoluted, really don't know how to assist you.

HINT 1:check fuses first???????
NO ENGINE STATED AND WORK DIFFERENT.
the free FSM book is here
https://www.jeepdied.com/
read that? HVAC and cooling chapters.

heater does not blow hot air AT VENTS.
does that mean blower dead?

is hot AIR knob at hot zone.?
is fan on high, :"?
can you hear a normal sounding fan on high???????
does it fail in recirc mode and vent??
Does hot are work with car moving fast?
is engine at 180f or more>using tools to measure rad temp?
OR LEARN TO USE SCAN TOOLS
SEE ECT AT 180F+ AND KNOW AT FULL TEMP.
yes,/no, if engine is hot, and AF LEVELS ARE FULL
did you scan the pcm for hvac errors (DTC)
Then this is a HVAC failure.
some GC have a hvac calibrate mode, read the Fsm ON THIS.
some have the climate control option, do you,????? very important fact to know.

EVER FLUSH THE COOLANT SYSTEM IN 12 YEARS.
HUMMMMMMMMMMMMMMMMMMMMMMMMMMM

WJ JEEP (got AZC?)
2002
HEATING CHAPTER, READ THAT?
see wiring-air-cond.......

http://www.morris4x4center.com/knowledge-base/index.htm?utm_source=cj#service

IF THE BCM CAN NOT TALK TO THE AZC
guess what. things fail
scan it
no scan it twice. and win..
only with AZC OPTION
SEE ALL THOSE lines bottom
lots of damper motors on each
COMPLEX. diagnosis. if present.
SEE PIN 4 BLEND


the Mtc WORKS TOTALLY DIFFR
The TVA below runs the blend door. motor. unlike aBOVE.


LOTS more IN THE BOOK.

Rarely do cars come with a block heater unless someone like the dealer installed it.

If you have one, it would look like an electrical plug like the one on a table lamp or toaster. It would likely be out of harms way but findable and accessible, maybe even poking through the front grill of the car.

Year, make and model? Some Fords have a bypass in the heater hose assembly. This does push coolant threw fast enough, causing the heater core to accumulate sediments, clogging it up. I use a 4 to 1 mixture of muratic acid(1) and water(4) to clean them out. Remove the hose from the engine(clamp off the bypass hose). Blow out the coolant. Use a funnel to add acid mix until it comes out the other end. Let set for about 5 minutes. blow it out( this is the bad part, because it sprays around. And it will get on you and it does burn somewhat). I do this at least two times blowing each direction in the hoses. This usually takes care of the problem on 90% of the cars I do. The other 10% replace the heater core. Big job there.

Looks like your mechanic messed up. If he has any integrity then he should take care of you. If not and you want to try and tackle it yourself then you have to ask yourself this: do I want to pull the dash out? Because that is what that will entail. Sounds like he may have messed up the ducting somehow. Unless the blend doors and directional doors are electric actuator operated in which case those actuators need to be replaced

I would recommend flushing your cooling system and especially your heater core.With water and compressed air. Possibly replacing your thermostat while your doing that too

Check the control cable that operates the diverter door in the heater box at both ends, to make sure that it operates the door when you move the control lever.

It is a big job.  I had to move my dash aft several inches to access the heater core.  Lots of disassembly.  Chiltons, all data, or any manual are a big help.