Okay ... I need some help on what the crap happened.

I was driving the truck (1985 F250 Supercab 6.9L Diesel) with the heat on. After 15 minutes of driving, I pulled into my wife's work, and suddenly smoke started blowing out the vents. It reeked of burnt rubber, and I had to quickly open the door and get out. I kept it running and popped the hood, cuz I thought that it was the engine. IN the engine compartment, there was smoke coming out from where I believe the blower motor is located. I realize that it's something to do with he blower, so I shut it off. Smoke ceases pouring out of the vents.

SO now my cab reeks of burnt rubber. I finished driving home, and before I shut it off, I was going to turn it back on to look into the smoke more. When I turned it on at home, nothing happened. No smoke. I've driven it for 3 days now with no more smoke.

Anyone got any idea's what could've happened to cause a one-time smoke incident related to the blower?

 

NO, you had two wires that had weak or broken insulation touch and short out agains each other, they got super-hot and melted away the rubber insulation around the wires causing the smoke. OR, you had a bad wire with too much resistance touching a metal ground and then it got super-hot and melted away the insultion causing the smoke. OR, you just have a wire all by itself with way too much resistance that got hot and melted the insulation off of the wire causing the smoke.

Either way you now have a burned up wire somewhere under your dash, it may have appeared to be coming out of the vents, but that is not always the case, it could be anywhere under you dashboard. I'll bet there is something that is NOT working right now, usually the burnt wire sets off a fuse somewhere before it melts down, you need to check all your accessories to see if everything is working: radio, electric windows, door locks, wipers, signals, high/low beams, a/c system, etc.

Also, you should NOT drive the truck until you find out what shorted out, you risk a fire or more burning of wires as you have a bare, hot, wire somewhere under your dash just asking to touch another wire going over a bump and set the whole ordeal in motion again. Get under the dash and find that burned wire, and trace it down to the problem that caused it in the first place.

 

https://www.ford-trucks.com/forums/8...g-trouble.html

 

blower resistor on its way out

 

I agree with scottddove. Sounds like a Heater Fire to me.

Where the blower motor resistor is located, and how leaves can get into the heater through the cowl, this happens more often than any of us like to think.

 

I had the exact same thing happen to my 85. I never did find anything wrong with it though. I had the entire dash out of the truck and couldn't locate any melted wires or burnt leaves.

 

I'll second the resistor... Did it smell like burnt leaves too? I had the experience once... Jumped out and dumped windshield washer fluid down the cowl... Pulled into WalMart and bought a fire extinguisher, have one in every vehicle after that one.

 

Pulled the blower motor today. Saw just what y'all described.

Inside the blower ring, was a wasps nest as big as the whole inside diameter. the bottom was completely covered in leaves and pine needles (there were even leaves and debris up the air hose to the blower engine compartment. There were leaves and debris stacked tight against the AC coils, and I'm amazed I was getting any air flow at all.

Didn't see anything burnt, so I'm thinking it must be on the other side of the AC coils.

Got out the shop vac and cleaned everything up real nice. Turned on the truck and I could actually feel air coming out the vents when it was on low.

Thanks for the tips and tricks!

 

Oh yeah ... I pulled the resistor/diode thing in the AC compartment ... it was filled with leaves and old dried debris. Good thing I didn't lose this truck to a fire!

 

Good to know I'm not alone! Everything works great right now. wondering what burnt.

 

Great news. I should have added that I thought it was funny someone was burning leaves inside the city limits when I mine happened! It was plumb full of leaves too... On the Dodge sites online it is called "cleaning out your closet", but you have to cut a port in the heater box to vacuum it out. Good to hear you got it though.

 

I think Ford must have recognized this problem at some date, because my 89 does not have the long slots in the air intake around the windshield wipers like the early trucks. It has small punched holes, so leaves and the larger insects are not getting in this one.

 

Yep.They started doin that in 87.I put a cowl panel from an 88 F150 on my 80 F100 because my truck sits for extended periods of time under massive oak trees,so the leaves were just piling up.Finally had enough and did the swap.No more leaves.

 

I installed regular aluminum window screening under the slots.

 

That's what I had done at first.But then the leaves made it through the small space at the edge of the screen,so I decided to swap.The newer Panel looks cleaner in my opinion.