ot dodge diesel not charging 806 Curt

I checked the batterys with drop voltage test the other day and both were .5 volts or less and everything was working ok then I took off the Boss snow plow and it stated showing no charge never shut truck off drove it about 4 miles and the gage dropped to 8 volts so I stopped and checked things unhooked the neg cable and it still did not move drove it home about 20 mins got home shut it off waited about 5 min and turned on the key and the gage jumped up to about 12 volts truck started and gage came up to 14+ in a few minutes and everything was fine until today when hooking up the boss plow it dropped again when checking this out I found something under the air intake there is a terminal block with 2 small wires coming from pos post on pass batt go to it and then they go across the front of the motor the front post on this block the side that goes across the front of the motor is loose on the block the wire is tight on the stud what does this do also I did a drop test on the pos cables and I got a reading of 6.54 volts out a booster cable across batterys and the gage went to normal take it off and it dropped to around 12 volts what is wrong

It just sounds like you have an intermittent bad connection. That snowplow that you have on there ties right into your battery cables to work. That terminal block that you describe sounds like the solenoid that runs that plow. The wiring for the snow plow could have been installed different ways so its hard to know for sure exactly how your truck is set up. But the bottom line is on your voltage drop test you said you got that 6.54 volts across the positives on both batteries. This should not be possible. There HAS to be a poor connection somewhere between them. You will have to trace that wire and check every connection between. The reason the jumper cables make it work is because you are substituting a better connection.

I know where the solenoid for the plow is the terminal block thing is factory dodge it is mounted up toward the fender on pass side above alternater and below battery