93 Honda accord overheating. New radiator, compressor, thermostat. Fans are not coming on. AC does not engage at all. Fluids Ok. Heater does work. Just got it back from shop. Help!

Hope this helps, do this VERY Careful, when over heating Turn ON the heater to full, does it cool down? does the water in the Radiator Boiling?. = water pump, (don't always make noise).
Not boiling?- Check and R&R Heat sending Unit Gage on the Radiator or somewhere on the engine maybe close to the Thermostat..

It would appear your thermostat is stuck in the closed position , find where it is on your engine, drain coolant and remove thermostat housing and stat, replace housing(liquid gasket OK) and coolant. now run engine, turn heater controls to hot leaving filler cap off, top up any water to max and replace cap now warm up to temp until fan comes on. if all ok replace thermostat with a new one and new gasket, you could also flush the sytem out at the same time with a hose pipe by loosening one of coolent pipes and flush radiator.

Check the radiator cap make sure the seal is good and it holds pressure. Or radiator pluging up maybe circulation is not good.

Replaced the temp sensor? "Burped" the system? Sure the thermostat is in the right way? You can even try running without the thermostat to see if that helps.

Thanks for choosing FixYa and welcome to the site. The fans should come on as soon as you turn the a/c on. There shouldn't be any delay. You could have a bad water pump, valve, or impeller. A bad head gasket can cause overheating also, but I would look into the pump first. Do the flush first. It may help. If it doesn't, look at the water pump.

This indicates that the booster fan for AC has failed. If you look in back of the radiator, you will see 2 electric fans. One is for the engine cooling, and the other is a booster for when the AC is running to provide for extra air flow through radiator and AC condenser. (May also apply when engine overheats, but not sure of that) As car is moving along, then air is pushed through allowing AC to work. When standing still, and fan failed, then no air (or less air) passing over condenser grill. (Condenser is the one in front of the radiator) No cool.
While standing still with engine running, open the hood and look at fans. Watch your fingers. Fans can start at any time. One may be running or not. Now turn on AC and look at fans. Both should come on together. If not, then it may be either the fan, or the fan relay or fuse. Or even the wire.
Does the engine get extra hot while standing still running? Let it sit there for ten mins or so and see if main fan kicks on. Watch your temp gauge, you dont want it to boil over. When the temp reaches the level it is at normally, one fan should kick on. If temp keeps climbing and no fan, then that may be the same issue, likely the main relay.

You will need to replace your heaters resister switch, which will make your heater work from 1 through 4 but is not your overheating problem. I would make sure your fan is working when when your engine gets hot.

the compressor may be low on freopn but, the fan problem is most likely the fan motor as it is the low temp fan and will run more often than both fans...to test see if you can switch the fan plugin to the other fan watch carefully that it does not get too hot as the second fan is a safety fan that works as high temp or when using the A\C

The cooling fans are supposed to come on when the ac is turned on,for some reason ,they did not,and the relief valve most likely let the freon out to keep the compressor from locking up,it will most likely need freon,and most likely the high pressure switch in the ac line will need replacing,this is what tells the fans to come on when the ac is turned on.

you may have a clogged heatter core. it you can do without heat, bypass the heater core and this may solve your problem