heat without engime compartment blower

yamajon · 10-20-2008, 02:45 AM

If you dont have a engine compartment heater blower,will your car still be able to heat the car inside?If so...how must the controls be positioned? thanks,john

vanwyk4257 · vanwyk4257's Garage

Without modifications your footwell blowers will not function properly due to the missing blower in the engine compartment.
If you search carrera heater backdate there are a couple threads discussing this. If you pull the rear cover off the electronics in the LR corner of the engine compartment, there is a control module that you can remove and modify. Basically you have to open the case (carefully) and remove the board/base. You can then solder a jumper wire across the reed switch and regain function of your footwell blowers.
The only caveat is that if your footwell blowers make any noise it will drive you nuts because they will run at low speed unless you turn them up. I had that problem with mine so I undid the jumper wire until I can replace the footwell blowers. There is a good thread with lots of pictures on the modification if you search. Best of luck!

KFC911 · 10-20-2008, 03:53 AM

Get rid of all the blowers (engine compartment and footwells), and you will still have PLENTY of heat from my perspective. The two levers are simply used to open/close the flapper boxes allowing heat to enter the passenger compartment. Caveat...I rarely sit at stoplights, but obviously, if the engine is at low rpms, the air flow is diminished. I still have an issue with "too much heat" rather than not enough

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Gratuitous pics of Carrera heater backdate...

Mysterytrain · 10-20-2008, 05:08 AM

Don't listen to KC...he's from down south

They don't get the butt chilling cold that we get up north. The footwell blowers are a great way to heat the cabin and by far work 100% better then my old engine compartment blower ever did.
Actually, I wish I was down south and running without blowers and had a longer porsche season.

KFC911 · 05:20 AM

. It does get pretty cold here at times...just not for months on end. Either way, with or without the footwell blowers, the blower in the engine compartment (and all the ductwork) can be eliminated and you'll have heat. If you desire to retain the footwell blowers, Ron (and Sal) have posted numerous great threads on how to keep them working. IMO, the deciding factor would be how long you typically sit at stop lights, etc. (with engine rpms at idle)...I rarely do, so that's never been an issue. Hey, I don't have A/C either and it does get HOT here, so what do I know?

ps: BTW Ron, "Infidels" has always been one of my favorite Dylan albums since it came out...with Mark Knopfler and Mick Taylor (Stones) on guitars, it's great!

spuggy · 10-20-2008, 06:22 AM

Quote:

Originally Posted by yamajon

If you dont have a engine compartment heater blower,will your car still be able to heat the car inside?If so...how must the controls be positioned? thanks,john

My '78 930 without engine or footwell blowers would be boiling water off the windshield (visibly steaming) a couple of minutes after starting with the factory H/Es.

With GHL's, not so much, and not so fast, but still enough heat to drive with the window down, which I habitually do unless it's raining hard...

ianc · 10-20-2008, 08:51 AM

Everyone always says to remove the engine room blower because the engine looks cleaner without it; ie. form follows function. Some people will also say removing it makes maintenance easier. That may be. In the winter, I drive my car and use the heat every day. I don't pull my spark plugs every day. Removing and\or reinstalling the plastic air hose from the blower to the tin takes all of two minutes.

For quantity of hot air blown, the more blowers the better, as is obvious.

Some caveats. If you have a Carrera, which has the footwell blowers, they may supply adequate heat by themselves, depending on where you live and what kind of driving you do.

If you have an SC (no footwell blowers), your main engine cooling fan (no engine room blower) alone will NOT supply adequate heat at idle. This means that if you're sitting in a traffic jam in the winter rain, you'll need to carry a towel and be constantly mopping the dripping windshield with it.

If your heating system is in the least suboptimal, meaning flapper valves not opening all the way, leaky air pipes, etc, then you will also not get adequate heat.

Make your own choice, but the factory put those blowers there for a reason. A great deal of it depends, as I said, on where you live and what kind of driving you do.

ianc

Mysterytrain · 10-20-2008, 09:39 AM

Just to add to what Ianc stated my 78 had the original engine compartment blower and it was totally inadequate. After the rebuild I was running SSI's and no rear blower. I had a ton of heat while moving but zero when stopped. I also could not warm up the cabin before a cold weather drive. After I added the footwell blowers I had a somewhat modern and more civilized heating system. I think the factory new early on that the rear blower alone wasn't making their upscale clients comfortable and the footwells were the best fix until the redesign with 964.

EarlyPorsche · 10-20-2008, 09:53 AM

My 1966 911 with ONLY ONE HEATER HOSE WORKING/ATTACHED gets the inside so hot that you are sweating if you don't push the lever in some or close the blowers a bit. It actually gets uncomfortably hot. You really don't need the blowers in the SWB cars for sure.

afterburn 549 · 10-20-2008, 10:11 AM

WOOSES, LOL,I am in Alaska and NO blowers !! I have enough heat....!!! ,,,note -not my daily driver, But you will be almost comfortable dwn to freezing.........We all went on the CANAM run up north this summer...50000 feet high snowing and cold..no blowers and no power up there either !
Try it , come on over to the other side.........slipery slope of converts here

yamajon · 10-20-2008, 02:46 PM

So then tell my unknowing $%^^# What levers do I turn which way on my 87 Carrera to get heat...Cuz,I ain't gettin it...I have SSI's and M&K exhaust..No engine blower at all..What do I do???? I'm gettin a bit chilly....thanks,john

rllevin · 10-20-2008, 05:35 PM

yanajon--if you have the automatic heat control with the dial between the front seats to control it you don't have any levers. Since there are servos in that gizmo that open the heater box flappers I have no idea how you'd backdate Carrera heat with the automatic climate control. Anybody done it?

Red Devil · 10-20-2008, 05:47 PM

Quote:

Originally Posted by rllevin

yanajon--if you have the automatic heat control with the dial between the front seats to control it you don't have any levers. Since there are servos in that gizmo that open the heater box flappers I have no idea how you'd backdate Carrera heat with the automatic climate control. Anybody done it?

Ya gotta release the lever from the servo to the heater lever and pull the red lever to manually open the flappers. That auto heating system is a "BEOTCH"!!!

afterburn 549 · 10-20-2008, 07:35 PM

Uhh OHHH mine is so old ..did not have all that fancy stufffffffffffffffffffffffffffffffffffffffffffffff f