Help Needed Truck is possessed...

[jbo561]

as i was getting into my truck to go to walmart, i smelled a strong smell of something electrical burning. i opened the door and the a/c fan was on. and the truck would not start. i had went to the store this morning and everything was fine. this is the second time the truck went completely dead. i bought 2 new batteries after the first time thinking that was the problem. any ideals what would cause the a/c fan to be on if the ignition off?

 

[Tail_Gunner]

I'd look into the possibility of a fan relay gone bad. A lot of A/C & heater fans have a relay that is controlled by the fan switch. If that relay is bad, it theoretically could keep the fan running.

I could be wrong, but many vehicles I've seen in the past had some sort of fan relay.

 

[mustangmuscle]

5 gallons of fuel and a match

 

[JLDickmon]

the relay for the blower motor is in the underhood fuse block..
but the relay is on the power side, and the switch is on the ground side..

Tailgunner is right.. not many things are gonna cause that..

 

[mustangmuscle]

aw come one Johnnie no thanks to me. I helped talk you into that truck

 

[Bad Night]

Sounds like the fan control board burned up , don't know the actual name of it but look on pass. firewall and you'll find it . There is a harness that plugs in and they do melt down on ocasion causing this prob . I actually had to buy the wiring harness on one of my old trucks because it completely melted .

 

[JLDickmon]

Sounds like the fan control board burned up , don't know the actual name of it but look on pass. firewall and you'll find it . There is a harness that plugs in and they do melt down on ocasion causing this prob . I actually had to buy the wiring harness on one of my old trucks because it completely melted .

it's the blower motor resistor, and it would have to be shorted to ground in order for it to do what it did, and after that, it's highly unlikely it would "return to normal"
but I know what you're saying.
Actually, I have yet to replace on on a Ford product, although I do replace it along with said pigtail with great regularity on GM cars & trucks.

 

[Bad Night]

Yea much more common on GMs but I have had to fix it on two of my trucks , my 99 v10 and my 2000 diesel . I also had an 88 ford van that did it 2 or three times (it sat alot and I think it would corrode . I don't think he said it went back to normal but maybe I misunderstood . Mine actually melted down and the wires touched each other and the blower motor ran for hours until the wire , due to more heat or maybe cooling down a bit quit touching each other . Either way just a place to look . Please do let us know what you find though .

 

[JLDickmon]

Yea much more common on GMs but I have had to fix it on two of my trucks , my 99 v10 and my 2000 diesel . I also had an 88 ford van that did it 2 or three times (it sat alot and I think it would corrode . I don't think he said it went back to normal but maybe I misunderstood . Mine actually melted down and the wires touched each other and the blower motor ran for hours until the wire , due to more heat or maybe cooling down a bit quit touching each other . Either way just a place to look . Please do let us know what you find though .

I can see it happening on a wire resistor block..
most of these are solid state..

 

[Bad Night]

The actual plug area as well as the pigtail melted on both of them .