Engine Control fuse keeps blowing

[MattP]

Gen light came on a few days ago so I pulled my alternator and it tested bad.  I replaced it with a cheap reman and it still wasn't charging.  Today I notice that the 30A engine control fuse was blown so I replaced that and started the truck.  Bingo!  Everything was charging as it should.  I took the truck for a victory lap around the neighborhood and the fuse blew again.  Popped another fuse it to see if it was a fluke and it popped too.

 

Recently I have installed HID headlights, but don't believe those are the problem because everything worked fine for a week or so... on the same day as the headlights, I also installed a new bumper.  There were a couple of ground cables connected to the old bumper bracket that I moved to a spot on the body (new bumper didn't have a good location).  

 

I figure I am dealing with a short somewhere or a bad PCM?

 

Any thoughts?  Thanks in advance!

[Mopar1973Man]

This will show you all the stuff on that fuse.

 

[MattP]

Thanks!  If I am reading it correctly, it looks like the only thing that it affects is the PCM/ECM which regulates voltage to the alternator... and that's pretty much it on the 12v (on a 5 speed anyway).

 

This confirms my initial assessment.  If I install an external voltage regulator, it should remedy the issue, correct?

[Mopar1973Man]

No makes it worse. 

 

Best off installing a protection fuse on the blue wire. Then send the PCM out for repair. External regulators tend to over or under charge more because there is no battery temp sensor. This depend on where the regulator is mounted. Too cold over charge, too hot under charge.

[Evan]

KISS

 

keep it stupid simple.

 

I'd take new lighting out of the equation before moving on

 

 

 

[wil440]

Bumper is the frame... body isn't, have you got a good body to frame earth ??

 

And Evan you might want to check the above, although there is some truth in the merit of your quote

[MattP]

Thank you for all the replies.  I am still chasing down this issue but will definitely update when it is resolved.  

 

wil440, you are correct, I need to find a better location to ground than the body.  I will try that out.  Aside from that, I have all new battery cables and connectors to put on sometime this week (the old ones are stock and in pretty poor condition).  I am hoping that one of these will do the trick.

 

I tried a different ASD relay and that didn't make any difference.