vzdude

Also make sure to check the wiring near the brake pedal mounting, and where that wiring goes from the relay over to the blower motor. It HAS had the recall, and I've seen some sloppy installs and that wiring could have rubbed through. I would bet that the trouble is in that circuit though. It makes the most sense. Hard to see from here though! LOL

halfpint23

The owners manual has these fuses numbered bass-ackwards from the image of the PDC you used.

OTHER source of confusion is hubby's iffy memory. He's "pretty sure" it was what your schematic calls the F2 (IGN RUN). He also robbed a couple of fuses from other slots trying to get it going - trailer, ABS Pump.... and I didn't get there til the next day so am truly in the dark here.

I will waste a fuse and see which one pops. THEN can proceed to next questions, I guess. I will get upside down (OUCH< busted neck isn't going to like this) and put a light on the through-firewall wires and see about the chafing you mention, too, and get back with you.

My main problem is lack of time - I am on the road at 5AM, one hour commute, long day of engineering tech work, another hour -plus to get home THEN (assuming no grocery store - or tonight, DOL for trailer tabs) a dozen horses to care for and THEN hubby feeding...... I need a couple of clones, and younger ones would be better. Lotto tickie and new Freightliner is sounding better every day!

Thanks so much for pitching in with this good info, I do appreciate it!
Kate

vzdude

No problem, but the wires I mentioned aren't actually through the firewall. They go from the ignition switch down to a relay mounted on the brake pedal mounting. And from there they go over to the blower motor. That is what the recall does. Puts in a relay to take the load off of the ignition switch. If you don't have that then some dealer lied about doing the recall! There should be a pink wire witha black tracer and a dark green wire for sure. Can't remember what other color there was, but those two I know for sure. Look them over real good!

halfpint23

After all this time, lots of head scratching and help from several people (notably VZDUDE - thanks!!) the truck is running again.

Got under the dash last night, with rags to wipe off dirt and a good light. Never did find a pink wire with black tracer, but did find the heavy dark green wire - and the infamous add-on relay to the blower motor, just as VZDUDE promised. I believe that in my truck, an ORANGE wire replaced the pink/bk one, just for reference' sake.

I found no evidence of shorting or heat damage to any wiring, but the various bundles were pretty crammed around in there, so gently rearranged and straightened out to take strain off connectors, cleaned and made sure all connections were tight and good, etc. I did find a funky little connector block to the LEFT side of the dash, sown low, that has the feathered push-pin things to mount in holes in the steel lower dashboard strut. It was not mounted, and was laying against the sharp edge of the strut in such a way that it "might" have been able to cause an intermittent short across its contacts - though I could see no evidence of sparking in either steel or plastic. Whatever...

After tidying up as much as I could get to, I put NEW relays and fuses in all the places available in the PDC box (big underhood fusebox next to drivers side battery), mad my battery connections again, stuck key in ignition, said a few choice Words of Power, and lit her off... normal start.
WOOHOO!!! Happy Dance around the truck to the music of the Cummins Rattle!

Sobering thought..... shut her down, waited a few seconds and tried again - all is good. Still dunno for sure what the problem was, as electrical always seems to have multiple problems for me. I "suspect" I had a bad starter relay, but there were a few other things that could have contributed to the problems.
When I have time I'll unwrap the various harness under the dash one at a time, inspect carefully and re-wrap.... That's time-consuming work and will hopefully not turn up anything, but it's the only way to be SURE there's not a faulty connection or wire that will cause a future problem.

Thanks again to all who contributed their experience in chasing down this issue, it's been great to be able to access so many other more experienced people!