Porsche Enthusiasts Club Forum

Hi guys it’s Sunday evening which means I have spent another day playing with my new toy. Picked up a cheap stereo of Ebay to chuck in as I have had no tunes since I bought it which took the edge of a quick evening blast, now to the point of my question.
Where the stereo connects there is an earth wire attached to this in a bodged way was a terminal block with 50mm of black wire joint to 2 blue wires. Decided to disconnect & see what happened. Car started seemed everything ran ok, put down for later investigation.
Now the heater will only give out hot air no matter what the position of temperature control knob. When the 2 blue wires are earthed there is a noise from behind the dash like a damper moving or solenoid firing. My question is does anyone have a clue what the idiot who had this thing somewhere in the deep dark past has bodged with this, it looks like he has cut the blue wire & just picked up an earth from a convenient point
Any help would be a real help as I don’t want to pull all the dash out if I can help it.

Can't help with the stereo but depending on the age of you car the heater issue is probably the heater control valve of a leak in the vacuum line going to it to operate it. It is a little plastic unit looks usually black about 1.5" round with one inlet and one outlet and it should have a small bore tube pushed onto the top to operate it. It is operated by vacuum and the tube can get detached or split, you can check if it pulling vacuum by removing the tube and putting a wet finger on the end (see if it sucks) you can chck the valve operates by either using a piece of tube and sucking or using a syringe you should see the valve move up and down, they can stop fully closing which can be seen if with full vacuum you can still close the valve a little.

They are about £25/£30 I believe (long time since I bought one) and I think from memory it is either on the front drivers side of the cylinder head or at the rear of the engine near the bulkhead depending on model. It can be found by locating you heater hot water feed lines in and out of the cockpit bulkhead as the valve goes in line with the hot water inlet (I think).

If it is not the valve it may be a vacuum tube loose or split under the dash or on earlier models a plastic clip snaps on the wire linkage controlling the heater do a search on this forum or look in clarkes garage on the home page there are articles on finding a replacing this.