Hey Guys,

I rebuilt my alternator (I changed the bearings nothing else) on my 2001 1500 5.9 4x4. When I took it off I forgot to take off the (-) batt. cable. Therefore it sparked and blew the fuse. Got everythiong back together and put new fuse in. However, when I drive down the road for about 1.5 mile the batt. indcater goes down to nothing and check gauge light comes on. When the truck starts everything seems normal until 1.5 miles. Maybe even one mile. When I took the alternator apart I washed it and then sprayed it with wd-40 just the caseing, and the spindal I put a litttle grease on. I also pushed the black plastic down a little when I removed the rear bearing with puller and cracked the black plastic at the rear of the spindal just back part not the sides glued it back though. What did I do wrong??
Ben

 

You could very well have raped your electronics when you did that.

High Amperage > ECU/PCM.

The amperage coming out of your battery can easily arc past a blown fuse.

 

what to do??

 

If you're asking, you don't have the electrical know how to solve this yourself. My suggestion is taking it to a shop. There isn't a thing anyone here can tell you that will help you fix it.

Just the nature of electrical problems.

 

Question, If the fuse blew then why would the pcm/ecu be hurt. Also the truck is running fine other than this issue, I would think if the pcm/ecu got hurt truck would be actting funny.

 

All Viper is saying is that with that amount power, the current could still easily arc across the blown fuse.

I still say bite the bullet and buy a refurbished one (like the one in the link in your other thread) and see if that helps. If it doesn't, you can always take the new alt back...

 

That's how mine behaved when I forgot to plug in the plastic wire connection again after replacing the alternator. Maybe make sure that it's plugged in and well seated, maybe with a little dielectric grease on the contacts.

 

Well, Turns out that the alternator is charging at 11.6 volts what do you think that is? voltage regulator? Thanks, Zman
Ben

 

That isn't charging at all, might as well be discharging. Where are you measuring that gives you 11.6 volts?

 

Most likely the voltage regulator, which is inside the PCM on these trucks; had this happen on mine. you can pick up a rebuilt computer with warranty relatively cheap off of ebay (about $200)