Radio cooling fan?

[Porsche-O-Phile]

I just added a new Blaupunkt Key West to my 944's interior (pics later) but I've noticed that the back of it gets EXTREMELY hot (hot enough to fry your skin by even the most brief incidental contact). I can't help thinking that having it stuffed into a center console where there's very little if any air movement can't really help the longevity of the circuitry, so I was contemplating adding a little (2" diameter) PC-type cooling fan to blow some air in from the back over the heat sink area. Anyone else done something like this?

[pontifex4]

That's a hot area to begin with, though it is open at the back. If you pull the head unit and drop a flashlight in each passenger foot well, you'll be able to see the beam.

Head unit heat is normally the product of load, rather than insulation, though: what kind of speakers (if any) are you driving with the onboard amp?

[Porsche-O-Phile]

Stock speakers. I might upgrade to a newer set of Blaupunkts but they'll be basically the same (just newer construction). No sub or secondary amp (I prefer the Zuffenhausen Symphony normally anyway, this is just for having on long drives or sitting in traffic).

It's an early car too, so the mounting is slightly different. The heater control is directly above, which is kind of open (cables and stuff), the carpeted panels on either side of the center console that die into the dash are on either side. I may possibly cut some slats into the sides of the carpeted panels if I can figure out a way to do it cleanly or find some sort of small louvered piece to plug in there if I cut a hole. Then I could be sucking in air, blowing it across the heat sink and blowing it forward, towards the underside of the dash (which is where all the heat ducts and stuff are anyway).

I guess I'm just shocked at how blazing hot the back of that unit gets - and in a very short time. I literally had it on maybe 30 seconds and just bumped it with my finger. That instantaneous contact was enough to burn the skin. It's like a hot plate or waffle iron surface kinda' hot. Not something I want to enclose on three sides with semi-combustible material and no airflow.

[Grandad#3]

Hi Jeff, I would contact the place you bought the Blau from and tell them how hot it is getting. I would think it should not get hot enough to burn you. Dose not sound right to me. There may be an internal short againtst the case to make it get that hot.

Cheers,
Larry

[HondaDustR]

Hmm...my Sony unit also gets that hot as well. There's a mounting screw hole on the back of the cooling block that I've been tempted to bolt an old computer processor heatsink and fan to, but I just never felt like doing the dirty work. I just figure it's designed to handle it, even if it would probably last longer running cooler. Most modern amps have overheating protection, so it would probably shut off if it gets too hot.

[Porsche-O-Phile]

Yeah I ran the unit for over an hour with no problems, so I'm sure it's okay handling the heat, I just don't like the idea of all that heat building up in the (mostly enclosed) area behind the center console. Besides, even if it CAN handle the heat, making it cooler will undoubtedly make it last longer.

Computer CPUs get crazy hot too - I'll probably just rig up a similar setup - a finned heatsink with a fan on top. I just want to get some airflow under there

[pontifex4]

It certainly would last longer if it were cooler, and I suspect something is up if your decks are both getting that hot. I'm not familiar with the early dashes, but all HUs are designed to run with <1" airspace on all sides.

Does it get that hot if you pull it out, leave it plugged in and run it balanced on your shifter? If so, I suspect that you either have a bad deck or a short which is loading up the amplifier.

[Porsche-O-Phile]

No, only when it's actually powered up. With the power to it off, it's stone cold.

[pontifex4]

Jeff, by "pull it out," I meant that you leave the harness plugged in, and run the deck (and the car) with the whole deck exposed to the air, not in place in the dash. Sorry, that was a bit confusing.

[HondaDustR]

I just figured 12W RMS (54W max) x4 would probably not stay super cool with just a small, minimally finned block of metal as its only cooling device.

[Porsche-O-Phile]

Sorry about that - yeah I ran it exposed (half pulled out sitting next to the shifter) and it was hot to the touch still, but I also ran it for a good hour and a half like that without any issues. I'm sure it will work pushed in (I ran it for a few minutes like that too) but I just want some better ventilation. No biggie. I'm off to retrieve a PC finned heat sink and a little cooling fan. That should work fine.

[pontifex4]

Take a photo of the fan once you have it installed!

[nightheart]

what are you going to wire it into for power?

[Porsche-O-Phile]

Well I dug around in my box-o-computer-junk and found what I think will be the perfect thing - the fan and finned heat sink from an old Pentium II processor. It MIGHT be slightly tall (if so, I'll zap one row of fins off with a Dremel tomorrow) and try it out. Should be really simple - I'll just tap into the power antenna circuit for power and the common ground in that area, that way it will always run when the unit is powered up. Pretty simple. Pics tomorrow when I get around to doing it up.

I'm surprised nobody else has done this - the newer, higher power, fancier stereo head units these days (with CDs and MP3 and lots of amp power compared to their 1980s counterparts that were originally installed) do tend to run hot - this is after digging around on some other boards and talking with some stereo "expert" guys locally. So I guess these sorts of temps are normal and radios just run hot these days.

In some of the airplanes I've flown, the avionics stacks do have cooling fans too, so this isn't all that unusual. I'm just surprised nobody else worried enough about it to do this yet. Anyway, pics forthcoming. Should be really simple modification.

[LonyB]

I have the same unit in my 944, got from Fry's for $59.00 on sale it's been in there for a few years now and no problems, it's pushing 4 Sony explode 4x6s and sounds great, also loud enough to drown out the cars stereos next to me at a red light.