Magic Smoke

[tnbumper]

Was driving my '86 F150 today and thought I could smell the local fireplaces. Nope. It was my truck. The cab filled with smoke pouring out of the vents. I turned it off and pulled off the road in front of my church, baled out and reached back in to get my Mt Dew, priorities. Popped the hood and found nothing smoking or irregular there. Got the smoke cleared out and decided to head back home with it as I was only a mile or less away. Started it up and began driving down the road again and immediately the smoke, definately smelling electrical, so I turn it off again pulling over, this time in front of the VFD! Same thing again, got the smoke cleared and continued towards home, stopping one more time at the cemetery. Last short run and coasted into my drive and disconnected the battery. It ran great and know the problem is located in the cab. Pulled the instruments, radio, and glove box to gain access to the the 'guts' of the dash and looked for visible signs of melted wiring insulation. Ran out of daylight and it's freezing here so I'll take another look in the morning, but I'm leaning towards the power feed for the blower switch. Odd thing to me is that no fuses blew and I could repeat the problem. I may start by pulling the fuse for the heater and see if I get smoke. Don't want to burn the truck up and need to use it tomorrow for a parts run. I've been thinking about pulling this drivetrain, 5.0 with AOD and putting in my bump, maybe I thought too loud and the '86 (slab?) is retaliating. Any ideas or anyone experienced this? Thanks!

[Racer Z]

Check the feeds to the ammeter (amp meter). It's probably the only thing not on a fused circuit.
Just in case you didn't already know, the ammeter measurer current to and from the battery.
Did you say that you disconnected the battery and it ran without smoking?

[tnbumper]

I meant I disconnected the battery after I got it home to shut off power. It ran great before that, even when smoking. I'll check the ammeter wiring, I didn't consider that circuit not being fused. Thanks for the info.

[papabug71]

Dang man, sounds like something got hot. Thank God it didnt burn to the ground.
Get on your back with a flashlight & start checking all the wiring under the dash. You'll need to undo the big bundle of wires to inspect each one. If it was smoking, it definitely melted some insulation off a wire.

I wouldn't risk running it untill you track the problem down. It's too risky

[Thunderfoot]

Check the feeds to the ammeter (amp meter). It's probably the only thing not on a fused circuit.
Just in case you didn't already know, the ammeter measurer current to and from the battery.
Did you say that you disconnected the battery and it ran without smoking?

The ammeter IS fused, they are located on the red and yellow wires by the alternator/solenoid area. The Amp meters on fords are a Shunt system so they do not run all the power through the meter.


I would check the heater blower motor and the resistor pack on it for the speed control.

[fordman]

what i usually do is start the truck and trace the smoke to where it is coming from. when i find the location i shut the truck off and investigate more deeply into the place where the smoke was coming from. di dyou try to just turn the heater off instead?

[67fordman1]

My goodness, first a church, then a fire dept., then a cemetary! Good thing your next stop was home! Seriously, glad it didnt burn down with you.

[70_F100]

My goodness, first a church, then a fire dept., then a cemetary! Good thing your next stop was home! Seriously, glad it didnt burn down with you.