95% electrics dead

[dwolkomir]

Out for a drive yesterday and while accelerating away from a light at half throttle truck suddenly dies, lost everything like a master switch had been thrown. Got it towed home and the only things working in the truck are gauge lights, interior lights, headlights, parking lights, rear running lights (no brake lights) fog lights,mirrors, hatch release and horn. No gauges, Windows, radio, starter, power locks, etc... I have 12 volts going to the starter, and at the back of the alternator, fusible links are ok, no power to any relays on firewall, no power at the 2 screw junction on firewall next to the blower motor, no power at relay on blower motor housing. pulled and checked every fuse, and shunt in the fuse block, even the blinker relay. Any ideas?

 

[Beavis]

Re: 95% electrics dead

Ignition switch under the steering column?

 

[dwolkomir]

Re: 95% electrics dead

Is there a procedure for checking the ignition switch? Gonna start checking all the grounds and the wiring at the starter next.

 

[dwolkomir]

Re: 95% electrics dead

The truck does have a battery relocate to the rear with a kill switch.2 gauge fused at the battery runs up to the engine bay to another fuse block that sends a 4 gauge directly to the starter and an 8 gauge to the alternator stud. power is good all the way from the battery to the alternator and starter, checked it pre and post fuses and at the alternator stud and the starter solenoid. the famous purple wire at the solenoid is looking rough, probably needs replacing, but I don't know if its related to the current issue.

 

[sly dvl]

Re: 95% electrics dead

That purple wire will have nothing to do with your problem. It might be a no-start down the road, but it's irrelevant right now. Dave's right, you must have a fuse link gone. There are very few things that could take out as many electronics as you've described all at once.

 

[dwolkomir]

Re: 95% electrics dead

I jumpered the alternator stud to the 2 screw junction on the firewall and she came right back to life. I replaced the 2 fusible links on the 2 wires at the alternator and nothing happened, must be a bad wire or another link somewhere further back. On the alternator stud I have the battery lead, the 2 wires with fusible links and a wire with an inline 10 amp blade fuse. One of the 2 wires with the fusible links seems to be the problem, can someone tell me where those fusible linked wires go, or what they power so I can figure out the bad one through elimination? I suck at reading wiring harnesses!
Thanks!

 

[dwolkomir]

Re: 95% electrics dead

Never Mind, I got it all figured out with a little trial and error. The bad wire is the one running to the 2 screw junction, the other is the ignition circuit and works fine. I will have to pull and replace the wire to the junction and we should be all good. Thanks for the help guys!

 

[sly dvl]

Re: 95% electrics dead

Kinda strange. After looking at the schematic I would have said the other link was the issue. One fuse link feeds the junction block then goes to your lighting system, and since they still work...???
The other fuse link feeds your IGN. switch. That's the one I would have guess was the problem. Either way, glad you sorted it out. :tup:

 

[dwolkomir]

Re: 95% electrics dead

My electrical terminology is lacking but I can read a multi-meter and use a test light. The fusible links were fine. There was some very poorly done splicing of the 2 fusible links and their associated wires at the alternator stud that was done by an infamous typhoon expert shop in NW Illinois when they rebuilt my motor over an extremely extended period that may have been the root cause of the multiple failures. I cleaned that all up with new fusible links, crimp connectors, and actual heat shrink instead of twisted wires and electrical tape. Also ran a new length of 10 gauge wire from the alternator to the B+ firewall junction. Hope I don't have any more issues with their work.

 

[dwolkomir]

Re: 95% electrics dead

Thanks for the heads up, I guess I will have to dig a little further into the harness and see if they messed with anything further up the line. Like I said before I am not good with the electrical schematics but it looks like it should be a single continuous wire from the alternator to the c100 bulkhead connector right? I have by by-passed it completely already so maybe I will just work it out of the harness and discard it if doesn't have anything extra spliced onto it incorrectly.