Grounding issues - help required please!

[Black 535i]

Lately I have had the outside temp sensor go wonky. It registers -37F all the time. I changed it out and the new one did the same thing. Also when I honked the horn it made the display go to -37F as well. Found the grounds and they were both in the same location in front of the left front wheelwell in the engine bay. Cleaned the wires-did not work. Removed the grounding strap, cut it off, stripped the leftover wires, twisted them, soldered them and reattached it but to no avail. Still getting the -37F temp display in the car and it also does this when I honk the horn. Anyone ever had this issue or have any further input into this? Maybe there are some crossed wires somewhere else someone knows of? Would really like to get this annoyance taken care of soon as I am tired of getting the gong for the temp every time I hit the horn or even when I am just driving along somewhere!

[genphreak]

Have you checked for full connectivity between the OBD connector pins and the plug on the front mounted sensor/thermometer? It does this when the sensor is disconnected or the wires are broken.

[Black 535i]

This gong going off every 10 minutes is driving me nuts! Have to check all of the wiring between the sensor and the fusebox as well as the grounds in the footwell for the horn. Apparently there are some grounds there that could be causing the issue as well.

[Black 535i]

I ended up cutting the ground for the temp sensor and regrounding it somewhere else and voila - no more gongs for -35F. Apparently there was still a ground issue in the wiring loom and rather than look for it anymore I isolated it by putting that ground somewhere else.