CCU Delete?
10-29-2010, 04:49 PM
#16
Rennlist Member
Jump K20 (white black) to K1 (ground) for slow speed. Check condition/position of resistor in blower ducting because it probably hasn't been heated up since your CCU stopped working.
Jump K25 (white blue) to K1 for high speed.
Jump K25 (white blue) to K1 for high speed.
10-30-2010, 05:43 AM
#17
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Thank you.
Going to try this out in a moment. Do you have a list of the other fans?
I'm thinking, rear fan on, (one switch) front fans on, (another switch or DPST) = demist!!
Servo's working fine, at some point it's CCU out for a full investigation-repair or delete.
Oil cooler fan, G12 - open circuit, on.
Rear fan, K25 to K1, on.
Front fans, ?
Many thanks.
Going to try this out in a moment. Do you have a list of the other fans?
I'm thinking, rear fan on, (one switch) front fans on, (another switch or DPST) = demist!!
Servo's working fine, at some point it's CCU out for a full investigation-repair or delete.
Oil cooler fan, G12 - open circuit, on.
Rear fan, K25 to K1, on.
Front fans, ?
Many thanks.
12-07-2010, 08:39 AM
#18
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Bit of a bump here guys, any help appreciated...........
From the back of the CCU (non air con) which connections will run the front fans.
Rear fan is fine, resistor was open circuit, now cleaned and working.
All servos working, just no air flow and its bl00dy cold.
Cheers. R
From the back of the CCU (non air con) which connections will run the front fans.
Rear fan is fine, resistor was open circuit, now cleaned and working.
All servos working, just no air flow and its bl00dy cold.
Cheers. R
12-07-2010, 11:12 AM
#19
Three Wheelin'
Raymond,
It's not quite as simple as that. The cabin blowers are driven by the CCU via a final stage driver circuit which sits between the fuse box and the firewall. This is a bit of electronics on a huge heat sink which seems to fail quite readily. They come up on eBay pretty regularly but are over £400 new from Porsche.
Do the cabin fans not run at all?? If you turn on the ignition and set the temp control to the red dot the rear blower should come on. If you then turn up the speed for the cabin fans they SHOULD come on and speed up as the control is rotated. If they don't run at all it would suggest there is a problem with the final stage driver.
Regards
Dave
It's not quite as simple as that. The cabin blowers are driven by the CCU via a final stage driver circuit which sits between the fuse box and the firewall. This is a bit of electronics on a huge heat sink which seems to fail quite readily. They come up on eBay pretty regularly but are over £400 new from Porsche.
Do the cabin fans not run at all?? If you turn on the ignition and set the temp control to the red dot the rear blower should come on. If you then turn up the speed for the cabin fans they SHOULD come on and speed up as the control is rotated. If they don't run at all it would suggest there is a problem with the final stage driver.
Regards
Dave
12-07-2010, 11:26 AM
#20
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Hi Dave.
How the devil are you? It's been ages............
Thanks for your reply.
The rear fan comes on if I turn past cold, blue dot.
Nothing will bring the front fans on.
As a short term measure, I'm hoping to find a way of running them, not too 'heath robinson', but I'm looking for a solution.
Still keen to remove or complement the CCU.
Switch 1 Oil cooler fan, on or off.
Switch 2 Rear blower fan, on or off.
Switch 3 Cabin fans, on or off.
In addition, if possible, to delete the CCU totally, and I take heed from your advice earlier, but...............
Switch 4 hot or cold.
Switch 5 up or down.
That's about it.
I can operate the rear fan, K25 to K1
I can operate the Oil cooler fan, splice G13 with a switch, so that's 2 out of 3, almost there.
Cheers. R
How the devil are you? It's been ages............
Thanks for your reply.
The rear fan comes on if I turn past cold, blue dot.
Nothing will bring the front fans on.
As a short term measure, I'm hoping to find a way of running them, not too 'heath robinson', but I'm looking for a solution.
Still keen to remove or complement the CCU.
Switch 1 Oil cooler fan, on or off.
Switch 2 Rear blower fan, on or off.
Switch 3 Cabin fans, on or off.
In addition, if possible, to delete the CCU totally, and I take heed from your advice earlier, but...............
Switch 4 hot or cold.
Switch 5 up or down.
That's about it.
I can operate the rear fan, K25 to K1
I can operate the Oil cooler fan, splice G13 with a switch, so that's 2 out of 3, almost there.
Cheers. R
