Here's the setup...
Stock '49 F1 - 6V 226 I6
Rewired with correct wire gauges last year
Replaced a fried voltage regulator about 2 months ago.

Did some work that pushed around the ignition switch and other wiring. Drove about 4 miles, got into the driveway and had smoke in the cab. Shut down every thing and pulled the battery connections. Every 10 gauge wire cooked its insulation: Generator to Regulator, Solenoid to Breaker, Breaker to a relay for the turn signals. The Regulator Battery terminal cut out relay wiring was blackened. Nothing else was affected - including other wires on the same connection posts.

My question: Was all this possible due to a short under the dash? If there was a short, wouldn't that have prevented the truck from starting / running? Shouldn't I have expected the regulator or breakers to interrupt a curcuit?

Speak to me, oh wise ones.

 

Well, I don't claim to be wise, but I'm betting the grounded hot wire happened while you were on that 4 mile trip, probably right before the smoke filled the cab.

Since it sounds like the only non-stock wire that released its inner smoke was going to the headlight relay, I'd recheck that wiring first.

 

Thanks Joe
Amazingly, none of the other wiring was affected - the 10# was heated to the point of the plastic sheathing oozing through the braided covering. That stuff is all replaced along with the regulator.

DW

 

And it sounds like the wires that smoked are those not protected by the circuit breakers. All that Yellow 10 Gauge wire is hot all the time the battery cables are on.

So if something under the dash, like the ammeter wire shorted to ground, that would melt it.

 

Check the ammeter loop wire... sometimes the loop chafes the insulation off.

 

Will do. Thanks Ross