Disconnected then Reconnected Battery and now rear engine blower not firing up

[moo75x]

So as a result of swapping out the steering wheel for a MOMO one I reconnected the battery and usual warning lights - roof and airbag (still waiting on pins to fit the resistor) but nothing major.........however i note the blower fan doesnt seem to be coming on when the ignition is turned on and as i recall it always used to...........does anyone have any suggestions whether these could be related? Its a 1994 993 C2 Cab........
Thanks

 

[decgraham]

Hi moo, I have a 1995 C2 Cab and my rear blower only comes on after a decent run. I sure Tore will pitch in and give you the temperature at which it cuts in and out. You can, if I remember correctly bridge the relay in the rear fuse box and force it to run. Also the blower cuts in when you put the car in reverse to stop exhaust fumes entering the cabin. Here is a link from a post by Jonttt which may help.

993/964 Rear Blower Explanation and fault dignosis

EDIT: scrap the original thread question. The resistor will be replaced due to the risk of thermoswitch failure causing an engine fire :o This is the original 964 USA market recall for earlier resistors which did not have the thermoswitch to protect the resistor from overheating: AFTER THE...

911uk.com

ATB

 

[911UK]

what @decgraham said

 

[moo75x]

brilliant - thanks guys, i just thought it always came on with the ignition switched on, obviously wrong on that score..................I'll give teh relay a little tap to see if its locked up in some way then try bridging it across with a teaspoon

 

[ToreB]

The rear fan shall run in two modes. Either when you need hot air to the cabin, or when the engine is hot enough to need the additional cooling.

Maybe you have turned the temp knob to a lower setting than before, or the environment/cabin air is warmer than usual?

If the cabin has the same or higher temperature as the temp knob setting, there will be no need for hot air, and thus the rear fan does not start.
To test the fan, turn the fan speed to 1 and temp knob to max. The rear fan shall then run on low speed.
Turn up to speed 2, and the rear fan shall run on full speed.
Cheers,
Tore

 

[moo75x]

What a star - Thanks Tore, i will do that little test, in fact you could be right about turning the temp down as it was warm at the weekend so it would hav ebeen reduced on the AC panel.

 

[moo75x]

So...............................I went in to do Tore's check and the ***** fired up straight away without even touching anything.............just turned the ignition on and there it went. Frustrating to say the east but thanks so much for all your help.......................

 

[jonttt]

If your really sad, you use a Bosch Hammer diagnostic and watch it open and close, something hypnotic about it (allegedly)

 

[moo75x]

I have tried sourcing one of those Hammer things - but to no avail so I am even sadder as that would make me happy lol