Brown wires seemed tight, reved it up to 12.7 and it drops to 12 when i turn lights on. This is so frustrating! What are the odds the ecm is really bad from factory? After sitting steady at 12.7 i can rev it up to 13.2. Second fan comes on its down to 12 with no lights on. Would a bad fan cause the drop when its not on yet?

Sound like the battery is dropping,not holding the charge. Charge the battery fully. Then see if the battery starts dropping just using your meter. Possible the battery was/is the problem all along. Plus here's the section from the manual on the charging protection circuit."The regulator takes the output of the 3--phase
alternator and applies it to the battery. SCR’s areused
to connect and disconnect the alternator from the
battery to achieve regulation of the battery voltage.
The regulator circuit produces current on the
BATTERY pin (Pins E & F). If a high voltage transient
is detected on the BATTERY pin this causes the
regulator to assume an open battery condition. The
high voltage transient will cause the regulator to turn
off for a short period of time. If there truly is an "open"
battery(short) then the regulator will remain off as the
minimum battery requirement will not be met. The
regulator will not turn on unless there exists a battery
voltage in excess of the minimum battery voltage
requirement."

The fan if worn(bearings) can cause a drop in voltage if the fan is dragging. The manual also gives you an amperage test on the fan and if shows above a certain amperage before it kicks on,then it should should be replaced.. The manual can show so many tests on different areas and components. That's why I push em all the time on people. First eliminate the battery as the culprit!

Ok so i got the charger on the battery now, i will let it charge all night, then get it load tested. Ill also grab the tester for checking the electrical things from work tomorrow. What should the amps be on the fan and where do i test it?

On testing the fan easier for you to get the 5 buck manual than for me to try to explain.. Plus it has a diagram of how to hook up the meter to test the fan and the amperage allowed.

All right, whats the odds ecm is bad out of box with a "pass" sticker on it?

With what I went through with all the ecm modules,the odds could be 50/50 you got a lemon.. But personally I never got one that was bad straight out of the box myself,but I replaced multiple ecms on the same atvs because they would fail.Again just eliminate the battery as a problem first. If it fails the load test,get a new one and see what happens. If it passes the load test,download the manual and go to the charging section and also the the electrical section that details the fan test.Plus the schematic can help you on the wiring.

Ok had it load tested at a polaris dealer, 12.4 volts on the printout it gave and says good battery.

12.4 is on the low end if that is all the battery can charge up to. Most can get to 12.6-12.8.As long as it passed the load test.Anyway just down load the manual. Go into the charging system tests. If you can't get over 13 volts with two different batteries,two different ecms,then possible the stator itself could be the problem.Plus have someone check directly at the battery with a good meter,don't rely on the speedo for an accurate reading. Plus the resistance tests on the stator charge wires are generally accurate,but not always 100% fool proof. Namely Chapter 10 is what you want to check: Current draw-- Key off, break even charge test, Alternator output test,and charging system testing diagrams.IF all this checks out,then possible you have a bad ecm out of the box.

If you are getting any resistance reading { you said 147 ohms } from any yellow wire to ground you have a grounded stator , it should read infinite { open } from any / all yellow wires to ground with the stator unplugged .

Yep over looked part of that post. Infinity should show OL or 1. depending on what meter he has. The .5 between each yellow is ok.(0.43 +/- 15 %) Possible he's reading it wrong,fingers touching leads??