built trans, acting like always in tow mode

[hot_runner58]

Hey guys, I'm new here. been reading info off of here for a while and decided to join. Unfortunately, I had a problem come up yesterday. I have a built trans that I have had more problems with than I care to think about. I finally thought I got it fixed last November, but yesterday it started kicking itself into tow mode. No tow light displays on the dash, but it revs up rpm like kicking it into tow mode. when it is acting this way, I hit the tow mode, and nothing changes. It does this from a dead stop. It was only doing it when in 3rd gear. The selector ring around D is also flashing. When I was doing my last test drive on it, it slipped twice while I was trying to cross an intersection from a dead stop. I went WOT, and the converter didn't slip. I checked fluid and it is a good red, didn't smell burnt, but it did have a brown dirt look coming from the dip stick when I wiped it. Any help is great! this is my company tow rig as well as dd.

 

[hot_runner58]

got it fixed. had the engine scanned, was showing low and high voltage spikes. I changed 2 new batteries and polished connections, all problems fixed.