Blower motor still runs after ignition shutoff. Ford Forgotten???

[kwazyca]

Anybody know why my buddies blower motor (heater/defrost/AC) still runs after the ignition is shut off?

He has to make sure all the heater/AC controls are off when he parks it or it drains his batteries.

He has a 2000 F-350 PSD.

Thanks,

Tom

 

[BJS]

Sounds like he's either got a short or a previous owner ??? has gotten creative with the wiring.

I'd start @ the fuse box and see if power is there w/ a multimeter and then see which side of the fuse it is on. Then see if you get power to the other side w/ the ignition on which would mean the splice is between the fuse box & the fan.

Basically you/your friend needs to spend hours w/ a multimeter chasing the wires.

 

[kwazyca]

That does not sound like fun.

This just started a couple days ago. So it is not a previous owner.

I wonder if it could be a bad relay?

Tom

 

[Ford_Forgotton]

yup, sounds like wire chasing to me also.

The heater motor should only run when the ignition is on. Since the heater motor draws a fair amount of current, it may run thru a relay, and that relay is prolly STUCK in the "run" position.

Im at work right now, so I dont have access to my FORD DVD otherwise I would look it up for you.

There are two places for relays. One under the hood near the brake mastercylinder, the other is under the dash on the left hand side of the steering column.

Use your owners manual to identify the relays under the dash, and then unplug say, the HORN relay and swap it with the HEATER relay (im assuming there IS a heater relay on this mind you).

If your horn doesnt shut off, you have a bad relay

 

[trackspeeder]

The Blower Motor Relay is located in the Battery Junction Box. 2nd relay.

 

[Max Power]

You could test to see if there is power under the dash at on the grey/yellow wire. This will tell you if there is power right back to the ignition. Also try unplugging the ignition switch and see if that fan shuts off. This will tell you if the ignition switch is the culprit.

 

[Max Power]

Also, does he have a remote start?

 

[Ford_Forgotton]

According to my DVD:

Violet/Orange goes into the relay junction box and comes out as Brown/Yellow to the function selector switch.
Black/Light Green is the HOT feed into the relay, and Brown/Orange is the HOT out to the blower motor.

V/O should be HOT ON RUN
B/LG should be HOT ALWAYS

 

[kwazyca]

Thanks guys.........We will get to work.

Tom