The ’98 suburban wipers have been occasionally intermittent over the last several months. How is that for being sufficiently vague? I think we first noted the problem over a year ago but it happens so infrequently that I can’t troubleshoot.
I had the other car at the mechanic and asked him what he thought. He said that it might be a circuit board or other connection inside the motor housing. Vibrations cause a connection to come and go. I had previously measured the current draw with the motor not moving and saw the following numbers:
Current draw non-moving 80/180 mA (Low/High)
Today the wipers decided to work so I was able to measure the current moving:
Current draw moving 3A / 5A
These numbers are approximate as the numbers vary all over the place as the wipers go through their cycle. For example, on slow it was as low as about 2.5 and as high as 3.5 so I’m estimating 3amps. I think the mechanics assessment is correct because if the motor was stalled due to a binding linkage or something, I would expect the non-moving current draw to be much higher than the moving current. Since it is lower, his assessment makes sense. Now to take it apart and see what I can find.
Also in a recent storm, the wipers quit near the house. In the driveway, left it running and popped the hood. 1 quick tap of a mallet to the motor and they’re working.
Update:
February 27, 2010. Well so far so good. The mallet travels in the car anytime I leave and will for another month or so until the likelihood of rain is reduced. But, knock on wood, ever since the on tap with the mallet, the wipers have not stopped working. I’ll keep my fingers crossed that I won’t have to whack the motor again, but just in case, I’ll be true to the Boy Scout Motto: Be Prepared!
May 5, 2010. Happy Birthday #1 Son! Over the past two months we’ve had a lot of rain (for our area) and the wipers have stopped on a couple of occasions and with one exception a single rap with the mallet has solved the problem every time. There was one time it was really aggravating because I could drive for about 90 seconds and the wipers would stop.
