Electrical - Hi this is my first time here. I have a 2006 chevy silverado 5.3 Vortec 4wd. My battery drained, I had a boost and it restarted ok, then ...

Hi
this is my first time here.
I have a 2006 chevy silverado 5.3 Vortec 4wd.
My battery drained, I had a boost and it restarted ok, then when I turned it off the dash lights, radio and battery light stayed on.I believe this is what drained the battery originally
I had the battery tested under load and it was determined it was at it's end of life so replaced it. We found when the wiper motor was disconnected the dash lights, radio and battery lights went out.
We replaced the wiper motor and problem did not go away, changed the cluster, checked the ground.Any suggestions?
The weather here has been sub zero for the past few weeks.
I can trace to when the problem started, I had not been using the truck for a few days so I would go out and let it run for 20 minutes as the weather was 12 degrees below zero, one day when I had started it I hit the wiper to clear some snow from the windshield and the wipers were frozen, they did free themselves, I turned the motor off after warming the truck up and it was the next day it would not start

Curious. May need to test the circuit and battery for current draw....then chase down the circuit affected if it is pulling too much by removing fuses until it goes down. Then you will at least know what system it is happening on. Obviously start with wiper and instrument cluster.

Thanks will do

This is the way to test for a parasitic draw: https://www.youtube.com/watch?v=KF1gijj03_0&t=279s

When I had problems that were weird like that I have found that cleaning all the ground connections has worked. Also I have replaced the ignition switch due to similar faults.

Thanks

We are going to do some further tests today, we have read on other forums people experiencing the same problem and not being able to find the cause have put a battery isolation switch on, unfortunately I cannot do this as my gas gauge does not work so I rely on my trip meter to gauge the usage, an isolation switch would set the trip meter back to zero each time.
Our thought were that if by unplugging the wiper motor, turns off the dash lights and the radio, we have replaced the wiper motor with a new one but the problem still exists. Could we put an isolation switch on the wiper motor?

I would continue to chase down the problem before doing something like that. Using the procedure above to find the parasitic draw and circuit so that you can narrow down were to look.

Why doesn't your gas gauge work?

It has never worked since I bough the truck, so always used the trip meter,