This is something that we don’t wish on anybody, especially during a heavy deluge. But it can and does happen. On an older car, the cause can be a broken or worn-out wiper linkage. On a more modern car, the wiper motor is probably the culprit. These are just two reasons why the wipers can fail. It could also be a grounding or relay problem—or a blown fuse. If the wiper stops working while you are driving under a heavy downpour, here are some very important things to keep in mind. This is based on our personal experience, but remember that safety should aways be a priority. Do not drive if you cannot see out of the windshield. I cannot stress this enough.
If you are traveling at highway cruising speed and the wipers stop working, just relax. Panic braking or drastically sawing at the steering wheel can lead to a much bigger accident. First, gauge the situation. Is the water beading off the windshield? Can you still see where you are going? If so, it is safer to just progress at a slower speed instead of coming to a complete stop on the shoulder. How far are you from the nearest gas station or rest area? If you can still see, travel at a manageable pace until you can pull over to a safe place.
Road spray from the car up ahead can muck up the windshield easily, and without working wipers, this can lead to zero visibility. Until you make it to a place where you can park away from moving traffic, hang back. Don’t drive too close to the car ahead of you.
Like when driving through a thick fog, we advise you to be more observant. Glance at the mirrors more. Turn down the stereo. Tell your passengers not to panic and that you have everything under control. Reaching out to wipe a small section of glass with your hand might sound like a good idea, but the would mean having to undo your seatbelt. Only do this if visibility is at zero. And even then, we advise against this.
Once you have found a place to pull over away from traffic, the most prudent thing to do is wait for the rain to stop. Don’t be a danger to yourself and others by deciding to press on through the rain. Again, we advise that you just wait for the rain to stop.
If you have spare parts, or are familiar with the proper grounding of your car, or have access to a mechanic while on the road (the old highways still have auto-electrical and surplus shops that line the way), then by all means fix the problem right away. But if not, better to just wait it out.
On an older car with a broken wiper motor linkage, it isn’t unheard of to tie a bit of string to both wiper arms and alternate pulling at it with your passenger. We’ve also seen people break a cigarette and spread the tobacco on the windshield to make water bead off faster. Great stories to tell after the fact, but we still advise against doing these things. These are solutions that, again, have risks. If the wiper is broken, pull over and wait out the rain.