Horrible Heating

Phat_Boy · 07-04-2005, 04:08 AM

Or should that be no heating at all. I have an 84 Carrera. I cant get even the slightest bit off heat to dimist my front windscreen. Way too dangerous to drive it at the moment, so its going to sit in my garage until the weather warms a little. What do i do. Air blows through the vents prefectly fine. There is simply no heat. I understand that they are a poor unit to begin with. How do i know for sure the heater is dead, are they hard and expensive to replace

Christien · Christien's Garage

Check this out:

http://members.rennlist.com/imcarthur/911autoheat.htm

Ian's done an excellent write-up on how the heating system works. Even though mine's different because it's an older model, it was similar enough that I was able to use his info to diagnose and fix my own heat issues (mine was the opposite of yours - wouldn't shut off so the interior was always blistering hot). I think many heat issues are really simple to fix with little or no cost, once you understand how the system works.

Just out of curiousity, where do you live that you're waiting for the weather to warm up in early July?

Hope this helps.
Chris

jbrinkley · 07-04-2005, 05:57 AM

these couple pages explain a lot.
http://www.type-911.co.uk/images/exhausts/heatingtech1.jpg
http://www.type-911.co.uk/images/exhausts/heatingtech2.jpg
http://www.type-911.co.uk/images/exhausts/heatingtech3.jpg
http://www.type-911.co.uk/images/exhausts/heatingtech4.jpg
http://www.type-911.co.uk/images/exhausts/heatingtech5.jpg
http://www.type-911.co.uk/images/exhausts/heatingtech6.jpg

Phat_Boy · 07-05-2005, 05:09 AM

Thanks for the help. However i think i seem to be missing the control levers on my 9 dial heater control box near the hand break...strange. Ive got more reading to do though
Its winter in Australia right now...

masraum · 07-05-2005, 05:15 AM

Yep, the heat in a 911 if it's right should melt you right out of the car. One important thing to remember is that the heat comes from the exhaust. If you need more heat but you know the system is working correctly then you may want to drop a gear and rev the thing up a bit. Get that exhaust hot.

Of course if you have the automatic heat (no levers and 0-9 dial) it's a different story since you've got sensors and motors and stuff. You'll want to get that stuff working correctly.

Hugh R · 07-05-2005, 07:34 AM

The rod inside the control box near the hand brake pops off and must be replaced/popped back on and the heat will probably work.

emcon5 · emcon5's Garage

Quote:

Originally posted by masraum
Of course if you have the automatic heat (no levers and 0-9 dial) it's a different story since you've got sensors and motors and stuff. You'll want to get that stuff working correctly.

Early versions of the auto head did have a lever, that would move up and down by the servo in the box.

The easiest way to troubleshoot is to turn the ignition on without starting the engine, and turn the dial on the heat box, you should be able to hear the servo. If the servo works, the problem is probably the connector rod has popped off the cable actuator lever.

Tom

Phat_Boy · 07-08-2005, 06:10 AM

Quote:

Originally posted by Hugh R
The rod inside the control box near the hand brake pops off and must be replaced/popped back on and the heat will probably work.

checked the control box, everything seems to be working fine. rod is conected and moving fine i think. moves the arm up and done when moving the dial between 0-9. Im at a loss as what to do next.

unclebilly · unclebilly's Garage

My car also had not much heat. I fixed it by making sure that ALL of the hoses were completely sealed at either end.

In my car, the hot air wasn't making it to the cabin.

Phat_Boy · 07-10-2005, 04:53 AM

ok, the heating actually produces some heat. however it seems to just heat up the dash vent on the drivers side. its quite hot to touch but no or very little air comes out, absoultely no heat comes out of the passenger side windscreen vent. could the hose have come out? anyone had this problem?

efhughes3 · efhughes3's Garage

Check to make sure all of the gates and such in front of the dash are opening and closing, also, you've got footwell blowers that should be moving the air toward the dash (as well as the main blower in the engine compt.). Mine was in sort of disarray, but after hooking it all up and replacing somne stuff, I've got decent heat.

WHERE do you live that you're still waiting for warm days in July?

Phat_Boy · 07-10-2005, 06:06 AM

Australia...still freezing down here!!! the footwell blowers seem to be letting in fresh air when they're not supposed to either...what did you have to replace to get yours working again?

efhughes3 · efhughes3's Garage

The plastic fan cages "welded" to the motors. I got a set off ebay, and replaced. Also, the hose that pulled air from the blower was disconnected, you may want to check that. Take the covers off, and their easy to inspect.

Phat_Boy · 04:47 AM

do they just pop off? i dont need to remove the dash? Also i only get the very slight amount of warm air on the right side...strange