Another one of our specialties, a Renault Megane with an electrical fault. These cars are a nightmare for a lot of auto electricians but we welcome them. We have a lot of experience repairing electrical faults with French vehicles including Renaults.
This car in particular had a problem with the hazards constantly flashing when the ignition was switched off. As we always do, we connected the car to our diagnostic machine to try and extract as much information from the car as possible to aid in the diagnostic process. Unfortunately a lot of people think that diagnostics is just plugging a computer into the car and it tells us what is wrong. If only it were that simple. Diagnostics means that we get as much information as we can via the vehicles computers to help us narrow down the area of fault, and then we have to start investigating with various test equipment to find the fault.
With this job in particular we were drawn to the UCH module after a lot of testing. As you can see from the picture water had got onto the board of the module. We removed it, cleaned the board and repaired the soldered contacts affected by the water. This did not cure the fault so we had to keep looking.
We eventually came to another system that controls the indicators, the alarm module. While trying to gain access to this we discovered the water damage in the boot. You can see from the picture the spare wheel well was full of water and had got into the wiring harness. This water had managed to get into the alarm siren and was causing it to set the alarm off and make the indicators flash via the UCH module. We had no option but to remove the module and clean the wiring harness to prevent any further shorting. We then put the vehicle on test to make sure there were no other faults. Once we were happy everything was fixed the car was returned to the customer with a full report.