BATTERY TERMINAL CORROSION
In this instance the car will seemingly suffer from every conceivable symptom: it may not start, it might cut out, warning lights may flash, the car can lose power, it might backfire – you name it! The fault is due to corrosion on the positive or negative battery terminal or both, and it’s worth inspecting for this sort of problem even if you are just servicing the car.
There should be a cover over the battery, but in almost every case this will have disappeared, with the result that moisture creeps in and promotes corrosion. If this trouble is not caught early, the affected connector/terminal will corrode to nothing and fall apart when touched. The terminals are only available from Renault dealers due to them being special assemblies that also hold fuses.
Another point to note is that the battery retaining clamp can corrode, which can prove a nightmare if you’re attempting to remove the battery. On this Renault and other models from the firm corrosion can cause numerous problems and these are often intermittent. Ideally, you should try to obtain a new battery cover – and a good covering of silicone protectant will help avoid any further problems. Unfortunately, Renault wiring isn’t very strong, so even a tiny amount of water/moisture will cause problems.