HVAC System

[85911]

I am working on my heater system on my 85 911. All blowers have been either replaced or refurbished. I checked the fuses in the engine compartment and recorded the following:
#1. 16 amp fuse- blown
#2. 25 amp fuse- blown
#3. 16 amp fuse- good.

The Owner's Manual does not identify location and calls for the following:
Rear window defogger, rear window wiper return (which I don't have) 25 amp
Heater fan 25 amp
Relay for heater fan 5 amp

My Porsche manual states the following:
#1. Heater blower relay 16
#2. Heater blower 25
#3. Defogger, rear window wiper 25.

Attached is a picture with the bad fuses removed and the positions are 1 on the bottom, 3 on top.

I assume the Owner's Manual is wrong and that I should follow the Porsche manual.

I'm wondering if there was a 16 amp fuse in position #3 because I don't have a rear wiper.

[wwest]

Some one has reverse wired your engine compartment fuse block?

Top to bottom for my '88 Carrera engine compartment fuse block.

1. Cabin heater control relay power.. Controls footwell blower power, provided cabin heater blower is pulling maximum current flow.

2. Cabin heater blower power, blower in engine compartment.

3. Rear window defrost grid power.


Footwell blowers stop if I remove #1

Cabin heat blower stop if I remove #2, as does footwell blowers, DUH!

Didn't test #3

[hdrockerroller]

Check the Bentley. I believe different years were wired slightly differently.