My Dodge D-150 V8 blows the Orange fusible link when the engine is started. At first it blew when trying to start it. I re-spliced (notice the blue barrel splice in the picute) and when it started this time, it again blew the same orange link. What causes this? How would I troubleshoot this?
I have confirmed it provides power to the Dark Blue wire that enters the bulkhead under the dashboard.

Please help! See attached pictures.

 

i think wat your suffering from here is old wires usually a fried link is a sign of a short finding it is the trick ive always hated finding shorts they are not easy check over all wires involved with the ignition system the blue wire is a main power supply to the circuit
good luck

 

There may be a short, or the charging system may have a problem with a massive overcharge condition, OR the bulkhead connector may be AFU, causing heating, etc.

I would do two things:

Temporarily wire in a 30A fuse and disable the alternator

To eliminate the alternator output and an overcharge condition, try pulling the regulator connector off and start. If the fuse blows, replace it and try starting the engine with the alternator belt removed. Don't run it long this way, a minute or two when cold won't hurt The reason for doing this is that you may have a wiring problem or internal alternator problem (One brush shorted to ground, example) causing the overcharge

If the above does not improve things, look the under--hood wiring over and "think." Has anything been added electrically which requires switched 12V? The "ignition run" buss IS NOT FUSED except for the fuse link, which is darn poor protection.

The "ignition run" buss (known as IGN1) feeds power in run ONLY (not accessory) to the instrument cluster for warning lights, temp and fuel, and oil pressure if equipped. It comes through the bulkhead and supplies

the regulator IGN terminal

the blue alternator field connection

the ignition system

electric choke if equipped.

On some vehicles, some smog doo dad.

How about INSIDE the truck? Anyone added a tach, gauges, other electrical accessory?

READ (please) this excellent MAD article. Even if you are not contemplating bypassing the ammeter, this article points up the pitfalls of all these vehicles

http://www.madelectrical.com/electri...p-gauges.shtml

Scroll down the page and examine the simplified diagram. Notice the "welded splice" in the black wire. This is a factory splice in the black ammeter wire, taped up in the under--dash harness. Branched off of this ALL UN--FUSED!!! is headlight switch power for the headlights only, power to the ignition switch, and a couple of other places.

Notice the photos of typical damage to the bulkhead connector. When these connections deteriorate, they build heat, which gets worse and worse.