[bmac]

Ok so I was driving home in the rain and had my wipers and heater/defroster on. Suddenly the cab was full of thick black smoke. Pulled off the road and used a tree to stop me from 50 to 0 in an instant. Jumped out thinking I was avoiding a fires but no. Just lots of smoke. Everything was working fine. All lights wipers engine. Everything fine. Im thinking maybe heater blower motor. I turned the truck back on. Started first time. No smoke. Turned on components one at a time no smoke until I turned the heater on. Came pouring out of the vents. Smelled like burning pine needles. Anyone have any ideas? Good news is absolutely NO body damage from slamming into that tree. None. I love my tank!

 

[Ranger429]

Well if it is only coming on when the heater is turned on then it has to be blower motor related. Could be a bunch of needles or leaves caught in the blower motor. Do you have A/C?

 

[bmac]

No no A/C. I just wanted to make sure that I was in fact making an educated guess and not assuming. Because we all know what happens when you assume. You burn up in an auto fire... Lol

 

[bmac]

Oh. And I could have sworn that I had cleared out all the leaves from the cowl. But that's exactly what im thinking happened. Just weird that it actually lit in the rain.

 

[Ranger429]

Well in a non A/C Bronco it is real simple to pull the blower motor but I don't think there is a place for debris to gather. As easy as it is to get to I would just pull the motor and test it externally.

 

[bmac]

Uhm...and how would I test it?

 

[Ranger429]

Hook it up to a battery. All you want to do is spin it to see if it smokes. Any squealing coming form it?

 

[bmac]

Ok cool. No not a sound. Heats just fine. This is going to be my first attempt at replacing a blower motor. Hopefully it's not the wiper motor. I want to fab up a late model wiper motor into it. And im not prepared just yet lol

 

[tonyroc14]

i wouldn't f around with this. If you dont feel safe driving it, then unplug the battery until you figure out what is wrong.

 

[Ziggy]

Could be that some pine needles got on the blower motor resistor pack and caught on fire. The resistor pack is nothing more then a 2-3 heavy duty wires that are coiled to produce a resistance which set the speed of your blower motor. This resistance pack is located in your heater box so that the air flowing across them keeps the resistors cool. If the air flow is disrubted by something (I.E. pine needles or leaves), the coils can get very hot under a load (heater blower running) and ignite the leaves or pine needles. Heater coil is located on the passanger compartment side of the heater box, should have two wires going to it with one or two screws holding it on, pull it out and look for evidence of burning on it.

 

[TheUnforgiven]

i'm sorry i have nothing else to add here (everyone has thought of everything i would say)

but i find it hard to believe you hit a friggin' tree at 50 miles per hour, and had no damage to yourself OR the truck. if this tree was big enough to stop you instantly, then somebody had to suffer damage and "lose'' that fight.

 

[BigWheelz]

X2 on blower resistors. Do you remember turning your blower down from high just prior to the smoke?

(Blower circuit only passes current across resistors on speeds other than high. For high speed current goes directly to the motor.)

 

[bmac]

Wheelz, I had just pushed the knob to the warm side. Thanks for the advice everyone. Really appreciate it.
Unforgiven...let me clear that up. I was doing 50 when I jerked off the road and started braking/sliding through the mud. Im sure I slowed down some but it wasn't much. Due to the short amount of reaction time available I didn't have time to fan away the smoke from the speedo to check my speed before coming to an abrupt halt. Maybe it's due to the fact that as an Infantryman im harder to injure/kill than the common everyday person? Maybe I have a Christine on my hands? Regardless, I certainly didn't mean to exaggerate my speed and wish to thank you for calling me out on it sir.

 

[TheUnforgiven]

i wasn't trying to start anything, just something i noticed. if you in fact have a Christine on your hands consider yourself blessed (cursed?), if you can only get it to fix itself mechanically. :haha

 

[bmac]

Its cool man. Just in a pretty bad mood last night. Lol

 

[bmac]

Ok. So, I pulled the fuse and disconnected the blower motor at the firewall and under the dash. But. As soon as the truck gets up to operating temperature smoke starts coming out of the vents again. Which leads me to believe that the problem isn't in the blower motor. Any ideas guys? I'm lost.

 

[Ranger429]

Are you sure it isn't a cloud of anti freeze?

 

[bmac]

Ranger, I don't think so man. Doesn't smell like antifreeze. Well to me anyway. But also I see your point. I don't know what else it could be BUT antifreeze. The blower has zero power going to it. Also I don't know why antifreeze would be coming out of my vents. But then again. It smells like smoke. Not antifreeze. Ugh

 

[Smok3y]

Are you sure it isn't a cloud of anti freeze?

And if it is, you better where a god damn respirator mask. Anti-freeze is a nasty nasty chemical. Fatal to eat, still harmful if breathed in. It's hard to mistake the smell of antifreeze with pine needles though.

Also, any possibility that dried leaves or pine cone/pine needles got stuck in the heater core itself? That is highly possible if you removed it recently or the door to it is open leaving it open to the elements....

 

[Ranger429]

Ranger, I don't think so man. Doesn't smell like antifreeze. Well to me anyway. But also I see your point. I don't know what else it could be BUT antifreeze. The blower has zero power going to it. Also I don't know why antifreeze would be coming out of my vents. But then again. It smells like smoke. Not antifreeze. Ugh

Anti-freeze smells very sweet. I am not up a 100% on the non A/C dash's, only had 1 apart in my time, but if the heater core is leaking under pressure the liquid somewhat vaporizes. IF you had no power to the blower motor and 'smoke' was coming out of the vents then I would start checking the box over very good to see where the smoke is coming in from. Does it smell like exhaust?

This is one of those "have to be there" moments.... diagnosing over a computer is way to hard without actually seeing what is going on.


EDIT: I suppose if it is anti-freeze even with the blower motor unplugged the vapors still would travel thru the duct work.