My 2000 Trailboss 325 has a short in the electrical system somewhere. The battery will not hold a charge especially when I have the headlights on. It's even worse then. When I turn the key on, the cooling fan immediately turns on. Do you guys think that is where the short could be? Or could it be in the headlights because of the fast drain when they are on? Any help would be appreciated.

 

I would start with the fan circuit. It shouldn't be coming on when the engine is cold. If the fan & headlights are on when the engine is off,,, that could absolutely cause the battery to die fast.

Of course, you could have a weak battery too. However, I seriously doubt that a weak battery would cause the fan problems though. So, you could have two problems (fan & battery).

 

The fan and lights do turn off when the key is off. I know I don't have a battery problem cause I'm on my third battery. Now that I think about it, maybe the light circuit is pulling from the battery even though the key and light buld is off. The battery does seem to hold a charge alot longer when I don't have the light switch on. for instance, after charging the battery it held a great charge for several weeks while riding during the day. While hunting one evening I needed to use the lights when coming out of the woods. As soon as I got to the truck the battery was dead.

 

sounds like your charging curcuit is faulty, thats why all your day driving does'nt drain the batt.in day it just alittle taillight+ignition.headlights are a huge drain if your not charging.

 

After thinking about it for a while, I do remember that when the lights are on and I rev the engine, the both the headlights and tail lights get brighter. That to me seems like the charging circuit is good. Am I wrong in thinking that?

 

That usually does point to a charging problem. However, if your fan is coming on when you turn the key on (even if the engine is cold) I would address that problem first. Or at least unhook the fan to see if your lights stay bright at idle. The combination of all those things running with the engine at idle could mimic a charging problem. It really does sound like you have more than one problem though.