Found a tekonsha P3 on craigslist for little ($45) so I bought it.
Order the wiring harness on ebay and got started.

I had read before that if you have additional off road lights (I have two) that those are plugged in under the dash in the place where the brake controller goes. So I checked and yes it sure was.
So I unplugged that one and stuck the one for the brake controller in.
Brake controller says current overload.
So I call tekonsha. The guy says cut the blue wire. If the brake controller works it is something else but that way you know if the controller works.
Of course I am not cutting wires but with a little bit of patience I get the wire out of the connector and test again. Controller works.
So he thinks I might have a short somewhere.
Now I know nothing about electrical, but luckily my neighbor does.
No faults any where so we look under the hood and follow the wires from the off road lights. The wire can be disconnected close to the fusebox so I disconnect. Love and behold now the brake controller seems to work properly!!!.
Controller is installed but iot does not recognize my trailer.
Now I have used my trailer for 10 years without brakes and I have to check on the plugs and wiring there.
I think I will take the truck to a trailer specialist to have it tested.
Once I know if that is all ok I will start working on my trailer.

Anyone know what went wrong and why in the beginning and why was disconnecting the wire under the hood the solution (I hope)

Feel free to chime in and otherwise other people might use my experience with this