1987 3.2 Carrera no hot air blowers

[keith.wilson]

Hi all.

Newb here with a faulty autoheat system. It worked until recently but now there's no blower assistance when I want hot air into the cabin.

I've tested various items and everthing seems to be to spec except for an open circuit in the exhaust sniffer near the LHS flapper box. The Bentley and Porsche manuals both suggest this would cause excessive heat into the cabin though, not none.

Could this also cause the whole blower system to stop, or do I have other issues, for example in the 12-pin relay in the engine compartment?

Any assistance gratefully received! Thanks in advance.

 

[NickCWebb]

When we first owned our 3.2, the blower in the engine compartment had a seized bearing on the motor which caused the fuse to blow. I seem to remember it was fairly straightforward to remove and disassemble the housing to get to the motor and free the bearing. Once that was done and fuse replaced we got hot air in the cabin once more (and were able to demist the windscreen!)

 

[keith.wilson]

Thanks, Nick. The motor is fine. I've removed it and put a battery across it - it runs just fine. I've done the test procedure in the manual on the blower control relay plug. Putting power onto pin 4 powers up the footwell blowers, and 5&6 power up the engine blower. All fine and dandy. So it's not the lack of power - just the lack of command to apply it.

I think I'm heading towards trying to find substitute relay/autoheat controller and see what difference they make.

 

[chas3.2]

Thanks, Nick. The motor is fine. I've removed it and put a battery across it - it runs just fine. I've done the test procedure in the manual on the blower control relay plug. Putting power onto pin 4 powers up the footwell blowers, and 5&6 power up the engine blower. All fine and dandy. So it's not the lack of power - just the lack of command to apply it.

I think I'm heading towards trying to find substitute relay/autoheat controller and see what difference they make.

Hi.
Do the flapper boxes open To let the heat in.

Charles.