Cockpit temp sensor fan motor

[robslade]

I've just been reading the new 993 Ultimate Owners Guide from http://www.pmmbooks.com/ (excellent book, highly recommended) and on p. 29 at last discovered the cause of my peculiar cabin temperature behaviour. Apparently the motor that pulls cabin air into the dash and over a temp sensor has failed. There is a little grill to the LHS of the steering wheel, in the climate control unit, so I guess it's behind there somewhere.

Does anyone know where I can get a replacement motor and how to get to it ? The sum of "about £1000" to replace the whole climate control system has been mentioned before by my OPC, so I've just been living with the symptoms (ie: turning up the temp as it gradually gets cooler during a long journey).

Thanks,
Rob

 

[plhorner]

On the 3.2, these fans (abeit similar) are prone to clogging up with fluff. Might be worth removing the fan and cleaning / testing before purchasing a new one.
Interesting you've brought this up Rob as it sounds similar to the symptoms I've been suffering, keep us all posted on the outcome and I might be tempted into the garage with the spanners to sort mine!

 

[Porker993]

I second the fluff argument. Worth taking out the unit and giving it a quick blow through.

Seems to clog up every 50,000 miles or so - depends how much fluff you have in the car, I suppose.

 

[plhorner]

ORIGINAL: Porker993

depends how much fluff you have in the car, I suppose.

You need to be carefull having a bit of fluff in the car! I find it can be quite dangerous, especially if the wife finds out.........[]

 

[dommorton]

Can you get them out without removing the column controls? seems a bit tight.

Mine was replaced by Paragon before I picked the car up as it was making a terrible noise on the test drive.

 

[robslade]

Thanks for the replies guys. As soon as the weather improves I will take out the CCU (will a bent coat hanger work or do I need a tool ?), have a look and report back. Should have done it ages ago but the cold weather reminded me.

BTW, I liked Phil's "fluff" remark. Reminded me of Xmas when I gave my mate and his twins a lift to the butchers in the 993 to pick up his turkey. The thing was too big for the boot so he sat with it in the front seat.... as we are driving along he turns to his twins in the back and says "don't tell your mum I had a bird on my lap in a Porsche" []

Rob

 

[Guards Red]

I believe the fan has a seperate part number and can be obtained from your OPC. It's a tight squeeze and the CCU does push hard against the stalks but will come out. Mine was in tight and need a hand behind the dash from underneath to get out. There are two connectors that have a metal release bar to uncouple them. The wiring will allow the unit to come right out though you need to feed it from behind has it snags on the radio like housing. The fan is bolted to the back of the CCU with one bolt and draws air through a rubber tube through the CCU. This tube and the hole in the CCU gets full of fluff after 15 years, it may be worth trying a vacuum cleaner with a mall tube taped to the hose first to see if you can clear the vent.

Rather than a coat hanger go to Halfords and get the tool. It's a standard DIN radio removal tool and costs a couple of quid.

Just a few thoughts, hope they help.

 

[clyde]

I have this problem and tried to remove the CCU to investigate the fan a while back but couldn't get it past the stalks. Mine's a left hooker, does that make any difference or is it just a case of using a bit more brute force and ignorance? Not sure I can manage the former but I've plenty of the latter []

Maurice - when you say that it runs forever, do you mean when the ignition switch is off?

 

[plhorner]

ORIGINAL: MoC2S



flattening the battery by running forever - it has a delay circuit which is prone to failure..


cheers, Maurice [8D]

Maurice,
Is the delay circuit built into the motor or the CCU? Is there a fix for this? This might be my problem, I recall hearing something running on after turning the car off but I've not suffered from a flat battery as mine lives on an optimiser.

Regards,

 

[Guards Red]

Hi Maurice,

A happy new year to you too!

As I understand it the lhd/rhd stalk layout is the same which means that for a lhd car the stalk in question would be the wiper one whilst for the rhd one it'll be the indicator/main beam. Both have similar arcs of movement and have a pull forward to actuate a feature facility. The only additional issue would be if you have the OBC stalk. If not it should come out lhd/rhd. But a little force required (like pulling reasonably hard on the stalk) and angling the unit has it clears the housing.

As for the fan running on, it should run on for some time after the ignition goes off. This varies depending on what the unit is doing. However it should not run on for too long, some report as much as 20mins but I reckon a couple of minutes and it should go off. If not you have a fault in the CCU, not the fan itself which is just a motor bolted to the back of the unit. There's a fix for this if you need it which involves a little bit of soldering inside the CCU unit.

Regards
GR

 

[Guards Red]

PS, the part number for the CCU fan motor is 964 659 148 00.

 

[clyde]

I had another look this evening to clarify what the problem with removal was and the damned thing just slid out without any issues at all. Maybe the cold shrunk it [][].

I have cruise control but the stalk didn't affect it's removal so I presume the OBD stalk on a rhd wouldn't either as the two seem to be pretty well mirrored (at least they are in a lhd).

Too cold to start removing the fan tonight but I'll have a proper look at the weekend. I'll try cleaning the 14 years worth of fluff out of the thing first though and see if that improves things as the fan is £148 on the Design 911 website []

 

[Porker993]

ORIGINAL: clyde

I'll try cleaning the 14 years worth of fluff out of the thing first though and see if that improves things

You'd be amazed at the amount of fluff I found in mine. I've no idea where it all comes from. The heating worked perfectly after I cleaned it out. Don't forget the "blow through" trick. You'd think I had a pet alpaca in the car.

 

[robslade]

I finally got around to removing the CCU this weekend, so thought I would post some photos to help/encourage others to do the same. Photos can be seen here:
993 CCU removal

Descriptions:
1) Get a pair of standard radio removing tools (£1.89 at my local motor factors). Insert into the CCU front panel holes until you feel a click and then reach behind the dash - there should be just enough space to get a finger on the back of the CCU. A gentle prod and it starts to ease out. You need to jiggle it carefully past the stalk.
2) When the front falls off and dangles by the ribbon cable, take care not to break the two small wires that connect the sensor to the PCB. The sensor sits "suspended" in the inlet pipe (RH end of the PCB). You can see that the rubber pipe in the body of the CCU is supposed to attach to the inlet, but mine was mangled.
3) Remove the two connectors at the back of the CCU (one clip on each at opposite ends, and the connector then hinges back and unhooks).
4) Close-up of the temp sensor in the inlet pipe.
5) General view of the CCU with front panel removed (note there is a clip on the front panel cable connector you must prise back before pulling it out). You can see the fan motor on the back.
6) Close up of the motor, held on by two nuts. (This looks like a special fitting so I'm not sure if Maplin sell anything that will fit here ? Mine worked so it was not an issue).
7) Motor removed.

There was only a little fluff in my rubber pipe (!), and the motor ran and stopped when ignition was off, so I re-assembled it all and tested it by feeding the cable loom back through the dash, which allows the whole CCU to lay on the floor in the driver's footwell, where it can be tested easily with the ignition on. When re-assembling the unit, it's best to attach the rubber pipe to the front panel inlet first, then push it through the CCU, then offer up the motor - this makes sure the pipe attaches correctly at both ends. Mine had not been re-assembled correctly in the past and the pipe was not connected to the inlet as a result, hence not sucking any air past the sensor.

Finally put the whole thing back and go for a long drive to make sure it works OK (as if you need an excuse).

Hope this is useful,
Rob

 

[clyde]

Not sure what you mean by "when the front falls off ..." Rob. Did you disconnect something or did it just fall off by itself?

I've had my unit out but the front showed no signs of coming away front the rest of the unit. Not that I really tried, I was just confirming that it would actually come out at that time.

 

[robslade]

Clyde, The front panel on mine was only clipped on and fell off rather easily whilst I was manoeuvring the CCU body free, dangling by the ribbon cable. Maybe I was ham fisted, but I suspect my CCU had not been put back in properly in the past (you can see in the pictures that the metal surround into which the CCU slides is also coming free). Someting to watch out for, not a big problem.
Rob

 

[clyde]

Thanks for that Rob, I think I'll need to make a concerted effort this week-end to have a proper go at mine.

 

[JB 3.2]

Excellent write up and photographs Rob. Thanks for the info another job added on the 'Things to Do' list

 

[Porker993]

Sounds like your rubber pipe had come adrift, so there was no air running over the sensor. Not come across that one before. It needs to be re-fitted carefully during reassembly. No wonder there was a lack of fluff !

 

[robslade]

Yes, the fluff accumulation may now commence ! I won't know if it is solved for sure until I go for a 200 mile+ drive. The symptom before was gradually having to turn up the temp demand until, after ~200 miles, I was asking for one click off max just to keep the cabin at 18C.

My next job is new shox and RSRs from Gert at Carnewal in March, after the service and MOT in Feb. Oh dear, my wallet has just had a nervous breakdown [8D]