91 B150 RamVan 318ci 5.2L

Issue:
1 - Started as no-charge
2 - Found blown and crappy fusible links
3 - Found wire burnt through the 50-wire clump from firewall

Steps Taken So Far:
1 - Autozone said bad alternator (in-car test)
2 - Replaced alternator (no fix)
3 - Installed an external voltage regulator (cheaper than whole ECM if the regulator is the issue issue)
4 - Found burnt fusible links
5 - ~50-wire clump coming through firewall appears to have a wire that melted through (bad)

Questions:
1 - All fusible links looks shot and where they connect looks shot. i dont think i can splice a new one in. Can I bypass or do a workaround? Be very clear please.

2 - I dont see how i can do a quality job of fixing the burnt wire without unraveling all the wires or buying and installing a whole new wireing system.

 

The fusible link that definately failed is the 2:2 connection in bottom of pic (purple & brown(?) to an orange fusible link.

They lead to a cluster that I am guessing is just 12v or 6v+. Just got a voltmeter and no 9v battery to use it.

 

There is no 6v or 9v wiring as the vehicle is 12v. Tracing wiring is easy but also very time consuming. I recommend you take it to an expert if electrical wiring is not your thing.

Having said that:

There is no point in replacing _anything_ until you find the short. If you blew several fusable links I would say this short is a large one and there is probably physical evidence that will be easy to spot. I would disconnect the pcm and then use a continuity testor. Shooting random voltage into sensor wires going to the pcm will very likely destroy it and then you'll have 2 problems.

Start at the alternator and trace back. If you find nothing start again at the battery and trace back. You will probably have to unwrap most of the wiring harness. I would disconnect the alternator and have it tested. Autozone does this for free.

In the end you could replace the entire harness with one from a salvage yard vehicle but if you have not tracked down the cause of the short, it may very well happen again if not immediately. Good luck.

 

Apologies, I missed that you have replaced the alternator. I would check all underhood wiring. Everything before the fusebox. All wires after a fuse that did not blow, should be ok. You can certainly splice in properly sized replacement fusable links although some locations can be difficult. Unfortunately if the alternator or regulator failed and 20 volts went through your system that might have fried everything electronic. Hope not! I would check bulbs, car radio, and any small items that will run off a 12v converter. If those are all fine then I might assume the rest of the system survived as well but no guarantee.

 

My hood hind may have cut into the 50-way cluster right next to brake booster. This "may" have casued all problems...

1) orange fusible link fried (root cause/destination unknown). Goes to a splice with lots of other wires on left. On the right it splits to a purple wire with black stripe and a brown wire. Both look like they go the the 50-way bulkhead also?

2) Brake differential switch wire is burnt all the way up to the 50-way bulkhead. (1 wire plug to top of RWAL)

3) And the 4wire plug to back of RWAL has grey wire fried all the up to 50-way bulkhead.

Are they seperate systems like I think or connected? Doing a post abt going non-computerized.

 

Seems plausible. Here is a link to online wiring diagram information.

https://dodgeforum.com/forum/dodge-r...e-chilton.html

 

Thanks. I ran new wire from bulkhead to brake differential switch and replaced the fusable link. It charges now (yay) and I haven't tried running it with brake wire connected because I didn't want to burn stuff up again.

What kind of voltage/amperage should there be to the brake switch?