It might help to post a video.

Since your fans want to turn on, it definitely sounds like an electrical issue. You may want to go around and look at your grounds to make sure you didn't leave one unattached?

 

I went out and did a video, but the jerky, lights blinking never happened. It went up to over 180, fans never came on. But when I turned the a/c switch to 1, fans came on, ran without issue. It didn't seem like my thermostat opened either.. Temp got to 186.8 -- I turned a/c switch on, (fans came on) temp went to 179.6 it just didn't seem like the thermo opened.. Maybe I should redo it and let it get to 195 or 200

 

So fans come on instantly with car turned to ON, and I turn the a/c switch on.

So I turned them off and started car, and let it run for a bit.

 

Did you re-use your old T-stat? If so, then yes, I'd swap it. Use a genuine Honda T-stat too. You could also ohm meter out the temp sensors, and find out which 1 isn't closing (making an electrical connection). You could also use your IR temp sensor to help find out the temp it's closing at.

 

The fans should turn on when the temperature reaches above 200F.

Not a bad idea to replace the thermostat. How long did it take the coolant to warm up to 199F? Have you driven the vehicle yet? If the coolant temperature drops when moving, then I'd say your thermostat could be stuck open.

 

It took it along time to heat up to 199F at idle in the yard. I drove it 20 miles with the fans running (via a/c switch being on) and temp stayed around 183

 

The temp will climb slowly... what is a safe temp to let it get to, before I abort and turn on the a/c fans?

 

The sensors turn on at 200F, so I'd say 205.

The other way to test your sensor is to get some boiling water at 212F, remove the sensor and see if it reads closed circuit (~o ohm resistance) with a volt meter when you touch the sensor to the water.

Another way is to watch the temperature gauge. Turn on the a/c when the temperature gets to the 1/2 way mark. The other way to quickly cool an engine is turn the heat on full blast if you ever lose your cooling fans.

It does sound like your thermostat is stuck open. I think it is worth the ~$25 investment to replace the thermostat with the OEM Honda thermostat, since you just rebuilt that engine.

 

The top hose was hot/warm bottom hose was cool.. I've been up ALL night thinking about that thermostat.. and I do believe I did replace it (80% sure I did).
The heater will produce heat very quickly.

I'm trying to rule out the thermostat because of its location and the pain it will be to replace it if I did already and that's not the issue (lol)

 

On my 97 Accord 4 cyl, the temp gauge never goes above halfway (like a 1/4 distance mark) between the cold mark and the middle of the temp gauge. And that's with the AC turned off, or with it turned on. My 99 Accord 4 cyl is the same way...never going more than half way to the half way mark.