What is wrong with my truck??

if you told the mechanic what you told us and they didn't look for a short or parasitic drain then you need another mechanic , it could be the ignition but these things have to be tested , that's how a mechanic goes about things , anyone can buy and replace parts with guess work

I'm no mechanic... But I am an electrician.u or ur husband or whoever can take negative terminal loose make sure all doors r shut , light under hood is unplugged where nothing requires power lightly touch cable to terminal . if u see or hear small ark u definitely have a short somewhere. Where was smoke coming from? The other comment made before me is true . the device the auto part places use will not tell u what u need to know but really good mechanic shops have a high doller device they use to tell them where to start .. Good luck

There r a couple electrical components on the trans. That may b causing ur prob . if it was not doing it be for work was performed good chance that's where the short is.

it could even be obvious , a pinched wire etc. or one may have been worn from brushing against metal and decided now was a good time to short out

Could be ur abs module draining the battery My 02 TB LT did that. Ended up pulling the fuse on the abs system