Club 80-90 Forums

On a trip to North Deven 6 months ago I drove through a deep puddle in the pouring rain. Immediately after the incident my oil warning light came on. The light stayed on for about 10 miles and slowly died away. I assumed that it was water on the contact and carried on.
However, now everytime it rains the oil warning light glows. It does not happen on dry days or frosty cold days. The other day whilst changing the oil I found the sender unit and that looks happy and dry. The light does go out eventually but it is starting to bug me. My van is a 1985 Autohomes Kameo 1.9 watercooled.
Any ideas would be appreciated.

The cable from the sender gets brittle with age and the insulation breaks down and cracks.
Also many vans leak about the windscreen without obvious symptons but water may affect the connections/wiring to the relay in the warning system.
I'd make a new wire for the engine bay from sender to loom connector and see if that rids the problem. Genuine auto wire is preferred, but 1mm mains type wire will do the job fine for a trial period, but is only rated to 30 degrees and will break down quicker than the original.
Also how's the alternator ? I've recently seen a van with an alternator fault that also brought on the oil light. Changed alternator and all good.