Turned off running truck, immediately no horn, no lights, no power to cab

[Whisp]

Glad you found the problem, will keep this in my problem list.

Rick,
Would that it were fixed. Just the 4-ways work, nothing else. Making me a tad bit bozo.
=/

 

[CDX825]

Check your wiring on the passenger side fender. There is one connector with a large yellow wire that feeds power to both the lighting and the ignition. Both have separate fussible links as well. All that current running through that one plug creates an issue and will kill power to the cab.

 

[Whisp]

Check your wiring on the passenger side fender. There is one connector with a large yellow wire that feeds power to both the lighting and the ignition. Both have separate fussible links as well. All that current running through that one plug creates an issue and will kill power to the cab.

Justin,

I wasn't aware that was the main feed. I know that wire, I gave them a cursory check and QD and Fusible Links checked OK. However, I can't rule it out as it sure could be 'downstream', I'll go give it the them all a much more detailed inspection/test.

Thanks!

 

[Dieselcrawler]

Yes check the plug mentioned above. Seen many of them corroded or melted

 

[Whisp]

Check your wiring on the passenger side fender. There is one connector with a large yellow wire that feeds power to both the lighting and the ignition. Both have separate fussible links as well. All that current running through that one plug creates an issue and will kill power to the cab.

Justin ** (two stars) for the suggestion ---- Corey ** (two) for reiterating the need. Your suggestion was correct!

I would like to stress, no matter how good the connector looks from the outside, how well it performs using a multi-meter, nothing, and I mean nothing beats a through physical inspection. The wire mentioned above, connector and fusible links all tested great using a multi-meter. HOWEVER, when I separated the connector and carefully inspected it, I found the connection on the large-gauge side was deformed from heat and the blade was blackened. There was also a small bulge in the insulation from minor corrosion.

I replaced the QD with the metal innards of a crimp connector and covered it with two layers of shrink wrap. Power to the cab is just fine, starts with key etc! Now if I could get the glow-plug relay to work reliably. Time to upgrade to newer relay or go manual!

THANK YOU ALL!
Before I asked for your advice, I was at the point of letting the beast rust-away by the barn. I'm off to finish the brake / bearing & shock R&R.
Thanks again!

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[Gr8ful]

I've seen the dimmer switch cause crazy things so I'd replace it.

 

[Whisp]

I've seen the dimmer switch cause crazy things so I'd replace it.

Agreed, One is in the mail from Rockauto.com. An iffy dimmer switch is just another variable that I don't need.

 

[pastorjeep]

I am glad you found it. Had the exact same symptoms on my 84 and it was the same plug and yellow wire. Lost all power to the truck cab.

 

[bbjordan]

Wow, it never ceases to amaze me the depth of knowledge and experience on this site.

Glad you got it figured out.