Lots of abs codes!

So I have a 06 Titan that started giving me abs problems. First it read rear right sensor, so I replaced that and all was good for a few days. Then the light came back on for the rear left, replaced that one as well and all was good for about a day. Light came back on and this time it was for both rear sensors and abnormal battery voltage so I figured there must have been a short. Looked and looked and couldn't find anything. I ended up cutting the abs connectors and sautered them incase it was the connectors. Rest the abs light but it remained on for the left rear sensor. I've replaced that 3 times now and each time the abs light will stay off sometimes only for a few miles other times days but I can't believe 3 new sensors could all have gone bad. Evrytime I read the code I also get random readings that when reset normally don't come back on. I've had it read bad brake switch, abs actuator, abs pump ect also sometimes the brake light and 4wd light come on and I can't figure out for the life of me what it is. Could it be the actual abs module has gone bad? Or am I over looking something simple. I've checked all the grounds and all are good but if anyone knows if there is a specific ground for the abs system that would be a big help to narrrow the search.