Fan in dash???

[Mister Moe]

I'm a new owner of a '99 F350 - I've had an E350 for a while but my first experience with an F style. I'm hearing a fan-type (or motor) noise from under the dash when I turn the ignition on (engine not running). At first I thought it was the heating (or cooling) fan but that's not it - I can definitely hear THAT fan when it comes on. Then, the other night I notice that turning on the lights without the key in the ignition I hear the same fan noise from under the dash. I'm thinking that maybe there's a small muffin fan in there to cool off some electronics? Maybe I need to replace it to quiet it? The truck does have 200k+ on it so if there is a fan in there it might be tired.

Any help would be appreciated, I did do a quick search but didn't find anything.

[highraven99]

the only motor noise i can think of would be the vacuum pump but thats under the hood.

[HVAC SuperTech]

I think thats your vacume pump youre hearing.

[Mister Moe]

I don't think it's the vacuum pump - this noise happens with the engine not running, no key in the ignition - just turn on the parking lights and I hear a motor or fan noise start from somewhere around the radio area in the dash. It's not all that loud, once I start the engine I can't hear it. I'm just wondering what it could be...

[HVAC SuperTech]

i just turned the parking lights on on my truck and didnt hear anything except the chime telling em my lights were on.

[Mister Moe]

Nick, thanks for checking that on your truck. I'm beginning to think it's the radio itself - although it's kind of weird that some motor starts up in the radio when the radio isn't even on! I'll have more time to check into it over the weekend - maybe try pulling the radio fuse then noticing if the noise goes away. I'll post what I find. It's possible that there was some "creative wiring" done to this truck.

[HVAC SuperTech]

yeah, very well could be. you have a aftermarket radio?could be something in it?

[Mister Moe]

Well I'll be... I just pulled out the radio (factory radio) and there it is - there's a small muffin fan built into the top of the radio!! Sure enough, it turned on when I turned on the lights even though the radio is off. Maybe it's used for cooling the lamps along with cooling the electronics? Ok, at least I've found the source of the noise - either I'll live with it, try to lubricate it or look for a replacement.

On to steering problems... a little more complicated...

[03_Turbo7.3]

lmao..its the fan mod.. dun duun duuuuun!