by accident when hooking my batteries up in the boat after charging them the positive touched the negative post , unfortunatley I already had the wiring harness hooked up to my truck. when I went to start my truck the cluster started going haywire flashing on & off mph and tach spin up and down all check engine lights going on and off also the lock unlock horn going off while truck is running every 20 seconds. I tried to clear codes with smarty but codes would clear then immediatly appear again ! Then I tried taking smarty back to oem stock , and then clearing the codes again , I was successful returning the ecm to stock and clearing the codes but then when I went to start truck again it was dead not even a starter turn over sound nothing totally dead ? I then unhooked the batteries from the truck waited about 15 minutes then hooked them up again and the truck would start, I was 385 miles from home with a boat in tow behind the truck. I called the dodge dealer in modesto CA and they said to bring it in and they would try to do a reflash, so I got there and they tried a few different tests to try and isolate the problem and it seemed to work for about 10 minutes and then as I am driving out to head back home it started doing the same stuff I was able to get home but it was sketchy driving at night with the instrument cluster going on and off check engine lights going on etc the odometer is stuck and not working this sucks and all because I was hooked up wire harness to wire harness between my truck & boat trailer the problem with the positive touching the negative on the batteries when I was hooked up caused my computer to go sideways . any body else have this happen to you ? whats it going to take to fix?

 

Can't help you but to help others avoid it do as many RV haulers do . Run a seperate circuit with a breaker to your seven way for the trailer . Most have a toggle switch and only turn on power to the plug when needed .

 

I don't understand what the batteries in the boat have to do with this ?
They have nothing to do with your truck electrical.

 

My thoughts exactly!! OP mentioned something about charging batteries...were you using the truck to charge the boat batteries? But, again has nothing to do with the trailer itself.

 

It has plenty to do with when two systems are hooked together in opposite polarity. The batteries try to produce something in excess of 1,000 amps. wires tend to melt, and semiconductors fry under far smaller voltages than 12 volts.

 

i think the question is how did the totaly independent boat electrical system get conected to the trailer/truck system.
Clark

 

I'm not sure if I am understanding what happened? How would the boat batteries be tied in with the trailer wiring?