I have a 2000 Dodge Ram 2500 (5.9L Cummins Diesel) w/just under 200K miles. Today, when I started it up, there was quite a bit of squealing (hasn't happened before), then a puff of burnt-rubber smelling smoke and a pop, followed by zero voltage reading on the battery gauge and a fast-rising temp.

=>serpentine belt had snapped.

I replaced the belt and my rig was sluggish to start (unusual), w/more squealing. The belt wasn't moving, nor was the fan, A/C, water pump, or alternator.

However, the crank pulley was spinning and appeared to be the source of the friction that melted/snapped this second belt. After turning the ignition off, I manually checked each of the pulleys, and they all seemed to turn fairly easily, with the exception of the crank pulley which was hot to the touch. None of the pulleys felt loose, or out of alignment.

Obviously, something is preventing the belts from spinning, but I can't figure out what. This all happened very suddenly.

Any ideas/help would be much appreciated!

 

do any of the other pulleys have movement out of normal? Like a bearing going out, or one sticking under the pressure of the belt "not moving when the belt is on"?

 

From what I can tell, no pulleys seem to have "out of normal" movement (no play, all operate smoothly, etc.). At the moment, I don't have a third belt to install to test if one sticks under pressure of the belt...but when I tried to advance the replacement belt to check for proper alignment on the pulleys before starting it up, I wasn't able to get it to move. Given that the crank pulley doesn't move when the truck is turned off, I assumed that was the cause.

 

Turn your key on and turn on the ac so the ac clutch locks, then try to turn the compressor pulley. Had that happen to my 01 last year. If so, then unplug the compressor clutch until you can get it fixed, because when running the defrost, if im correct, will cause the compressor to kick on every now and then.

 

Do I understand correctly?

If (once the truck & A/C are turned on) the A/C compressor pulley won't turn, that may be causing the belt to bind and then melt/break? And if that is true I can disable the A/C clutch to prevent that from happening? And the defrost somehow causes the compressor to turn on = bind the belt?

 

you got it. the compressor pulley turns freely until the compressor clutch engages, which is when you use the ac. Also the compressor kiscks on and off when running defrost if im correct. google it and watch how many hits you get for it running in defrost

 

Hmm...interesting. Well Twistedtrax, thanks very much. I'll test that out, and hopefully it will work for me. If not, I'll be back with an update!

 

You are correct

 

very interested to hear about what caused the belt burn, and hope you figure it out before belt 3

 

Thanks newman1367!

Twistedtrax, I'll let you know what I find out. Thanks again for your suggestions and information!