How to wire a winch

[Divide Wee]

I want to install a small winch in the bed of my 2020 Silverado to pull my motorcycle up a ramp into the bed. Normally I would just tap the positive and negative posts of the battery and run cable to the bed. Given the lack of decent access to the positive post, has anyone found a good way to tie into the system? This would be needed to install a winch, snowplow or any other heavy electrical accessories.

[NM Pete]

Did anyone ever answer? I'm  having the same issue

[2k19Sierra]

Here’s the upfitter bulletin for snow plow jumper harness install. Use this but route to bed of truck? https://www.gmupfitter.com/files/media/photo/1363/UI Bulletin 161_wip.pdf

[Gangly]

If you are only using it for winching up 4 wheelers/ATV's, why not just utilize a portable battery box?  When not in use, place it in the garage on a trickle charger so its always ready to go and not taking up space in the bed of the truck.