Kitchen Large Electric Appliances - refrigerator not cooling

I have a tappan frig model 95-1549-00 freezer on top. Freezer cools good but refrigerator does not. Freezer builds up ice in the center of bottom shelf a couple of weeks after defrosting and cleaning. Anyone know possible causes? Thanks

From your description it sounds like you do not have a frost free fridge.
If I guess right it has a cold plate type freezer where the frost accumulates on the iside surface and the fridge has a cold plate on the back wall.

Is this so?

If it is and the frost line extends only part way into the freezer and doesn't make it to the cold plate in the fridge then it most likely is low on refrigerant.
The way it becomes low is that you will have a leak.

If a repair person confirms this you may find it worthwhile to just replace the fridge.
It is not permitted to add refrigerant without repairing the leak and the cost to replace the cold plate(s) would likely not be worth it.

If a freezer gets as cold as it should...not just cold...but you have to know it can get to say 0 degrees, or even less...then you have no serious problem.

Take a temp reading in yor freezer section. Can it get to 0?

First make sure that your freezer's evaporator fan comes on when the compressor runs. Does it?

If that is not your problem, then you could have an icing up problem up top.
This has several causes: The simplest being that your defrost line is clogged with sludge and when the freezer goes into defrost mode, the water has no where to go and refreezes in the bottom of the freezer section near the rear and in the defrost drain cup and baffle area.

To cure this, undo the drain line and blow in it from either direction; either through the top by using say a car vacuum tubing inserted in there...or blow from the bottom of the drain pan upward. If you know knew you had resistance, but then junk flew out and now it blows easily through...you have just fixed your whole problem

But say that your defrost tube already IS clear. THEN your problem could be that your defrost cycle got a glich and did not defrost. Even if this does this once or twice...there is now so much ice in there that the water can't all get out between cycles (of run and defrost) and refreezes.

You can advance the defrost timer manually to put it in the defrost mode. Defrost timers are located either at the botom underside of the refrigerrator (old method) and newer models usually have them right up next to the thermostat at the top of the refrigerator compartment. You will find a small round inset control that you can turn with something. Sometimes your tip of your finger alone can do the job. Turn it while the refrigerator compressor is running so that you know that when you turn it, that when the compressor stops running you know that you have hit the defrost mode. You can leave it there if you want because it will automatically advance...or should...after the defrost cycle ends.

Or, you can unplug the freezer and take all the food out into the sink and blanket it over to keep it frozen and put hair dryer in the freezer and run it in there with the door closed. Secure the hairdryer if you leave go of it unattended to make sure it does not "walk" from the vibration over to the eggshell thin plastic lining and melt it!! Also clear out the area of the refrigerator in the back of the refrigerator where you drain cup is and hair dryer up there.

I do this kind of work all the time and have resolved every issue and have never had to call an appliance shop...ever. Just so you know that I am not just throwing theories around.

Thanks to all for the advice. DaVeBoy you were right. The tube was clogged . I cleared the tube and now everything is functioning properly.What a great web site!

I'm glad this worked out for you.