Uneven running in the rain
Posted: Tue Sep 06, 2016 5:25 pm
Just to let you know of a strange problem I encountered a few weeks ago during that rainy period of June.After an hour or so motoring in the rain my convertible began to run quite roughly and stalled a couple of times at roundabouts. I pulled into a layby, switched off the wipers and the car ran perfectly.If I switched them back on it hesitated.Back home I plugged in an amp meter and turned on the wipers. At one point in their cycle an almost dead short showed -30 on the gauge,it then performed normally until the same point was reached again.The car would splutter or stall at this point.on stripping the unit I found the end float in the wiper motor was such that one of the worn brushes was riding up onto the main wires to the windings as the armature moved back and forth. The metal brush carrier burned and black.I know the ignition doesn't take power through that fuse,but a short of that kind can't be good for it.Anyway a second hand armature with new brushes has cured the problem so far despite a typical British summer and over1500 miles since.