Hi: this 94 is for the most part trouble free with the usual repairs/replacements for a truck of this vintage. It has spent most of the Winter not running but I did drive it week before last.

This morning I started it and within 100 feet, I could smell very a pronounced
fire in the making somewhere in the cab. No flames, small degree of smoke; possibly near the front or even from the front vents.

I checked the engine compartment, underneath the car and brakes-no signs of anything. The only slight smoke smell may have been near the vents.

Has anyone run into this or have any idea what this could be?

Thanks for your help. I appreciate it.

 

Just out of curiosity , where did you have the vehicle parked?
It's not unusual for visitors to move in if it was out in the open.
They get into the craziest places chew on wires etc. looking to make a new home.
You didn't hear it get chopped up in the heater blower by any chance?

 

No. No rats. Almost smells like wood burning. I just went out and ran the fan only. I can smell the issue...lightly but I don't hear anything grinding around n the fan. I am leaning towards the heater core or switch.

 

Mice like to move in where it's warm and they use anything they can get to build a nest . I did see a vehicle where the mother had 8 babies in the heater duct.
The blower motor resistor is placed in the ductwork and kept somewhat cooled by the air going past it. If a leaf or two got in there and contacted the hot resistor wires it could cause what you might be seeing.
A blower motor that is pulling too much current can put a strain on the blower motor switch wiring where it plugs onto the switch.

 

It doesn't seem to me that the blower motor resistor for a 94 Explorer is located in the duct work but rather in the engine compartment to the right of the blower motor by the ac unit. Not sure how leaves would get into the blower system. I just restarted the car with no smoke, no burning smell. Ran with A/C on. A/C off. Heater On. Heater Off. Ran the fan through all settings. No smoke within a five minute time period. Now I'm really at a loss. Not sure how to diagnose this.

 

Anytime the function selector is in any position except recirculate(Max) a/c the system pulls in outside air.It is all supposed to go through a cabin air filter if the vehicle has one and pieces of trees , leaves etc. get into the system and pass by the blower resistor on the way to the heater core or A/C evap depending on the position of the blend door. Garbage does get in there !