Does the factory make mistakes? in mirror temperature sensor
 

Ever since I've owned the car the digital dash outside temperature has always been showing -40 F over time I have searched for and seen several recent post about this with suggestions from cleaning the in-door behind the DS mirror connector to tracing broken wires. The idea that I would have a broken wire was always foreign to me as the car has always been maintained by Porsche shops prior to me owning so there's no bad PO evidence throughout the car.

I've installed a new sensor some time ago but that didn't solve the problem yesterday I decided to pull the mirror one again and by comparing each wire against the factory drawings (sheet 6, location D48 and sheet 4, location D21) I found that inside the multiple connector # T37 (located inside the DS door under the mirror, accessed from the outside by removing the mirror) one of the two wire from the outside temperature sensor was placed in the wrong pin location the #2 wire (male) pin was in the right location but the #4 pin was place in the #5 slot which is sup post to be vacant.

By moving the pin from the #5 location to the #4 location I finally got my in digital dash to read the right outside temperature.

So for those that see a constant F on your digi dash check your pins in T 37

Best :thumbup:

Glad you resolved the mystery. I'm 99% sure your car left the factory with the temp gauge reading properly however. ;)

hi what colour wire was for the sensor. mine has the same message on dash. I'm presuming the sensor wires are on the drivers door mirror. does anyone have a picture. thanks

Wires
 

Each pin in the plug located under the base of the mirror has a number on it that correspond to the wires that can be found in the wiring schematic.

That's the way I traced the issue. I'll have to search for the picture of the plug.

Best H

Consider that there are a few reasons why that connector might be disassembled after the car is in service. Most Likely is when a door needs to be refinished, or when the mirror itself needs to be refinished. Since the barrel connector won't fit through the hole in the doorskin, a connector pin extractor tool is used to pull each pin from the barrel inside the door with interior door panel removed. Wiring can then be extracted through the doorskin, and refinishing can be completed. On assembly, you stand a pretty good chance of getting the pins back in the right holes since you have a) the picture you took of the connector prior to disassembly, in tandem with b) the WSM wiring diagram, but also needing c) the ability to see and read the pin ID's on the barrel. The last item (c) is the toughest for me.

Yep.. my old white '87 S4 had mirror "issues"..

The passenger side wasn't connected at all - someone had snipped the harness between the mirror and the door. Solder and heatshrink and all good.

Driver's side someone had taken the pins out of the connector, and put them back in a seemingly random order. They got lucky, one direction worked (up/down pair). Everything else was completely wrong.. quite the headscratcher, especially as it had the memory option, so something like 9 wires to it :D