transmission flush help

I decided I would do the transmission flush today and everything went great except I am stuck trying to check the level. I used the wire to trip the number 4 and 13 ports, started the truck shifted from nuetral to drive and back 3 times, and didn't get any kind of light the first 2 times I tried this. Finally I redid everything and on the 3rd time I tried this the AT fluid light came on, but where it was suppossed to stay on for only 2 seconds, it stayed on permanantly. When I shifted into park it stayed on again. The only thing that I could think of is that the temperature was already hot enough, but the truck and only been running for maybe a minute or two while I tried this 3 times. I was going to just let it sit for 45 minutes or so to let it cool and try again, but thought I would post on here and see if anyone had any other tips, tricks, or could tell me if I was doing something wrong. I have to get this done tonight as I need my truck tomorrow. Thanks for any help.

 

If the "AT TEMP" light stays on, you're at proper temp. If it's flashing, the temp is too high. Good luck!

 

So it would stay on even in neutral before I even go to park?

 

Yes