Troubleshooting windshield wiper problem

[Daveroo]

My windshield wiper has stopped functioning, so I thought I'll try to do some basic troubleshooting first. Electronics is not my strong suit, so you'll need to bear with me a bit. I thought if I did some of the following steps I'll get closer to determining where my problem lies. My other electronics such as radio, lights, bilge pump, stereo, etc. are all in working order, so I don't think it is a general electrical problem such as dead battery. I thought if I put a multimeter to certain spots I'll gain some knowledge. First, if If I measured just past the breakers, I should register a reading and this indicates the breaker is OK and it may be the wiper motor. If there is no reading here, I would measure before the breaker and determine whether the circuit is live in front of the breaker. If still no reading before the breaker I don't know what I'll do. By the way, does anyone know what kind of reading I should see? Any advise would be greatly appreciated.

Daveroo

 

[gungadin]

Set the multi meter to dc voltage. Connect the negative lead to the ground ( either at the battery or ground busbar). If power is supplied to the switch through a breaker, check for power to both sides of the breaker (on and off). If you have power to the input but not to output with breaker closed, the breaker is bad. You can TEMPORARILY!! bypass the breaker, providing it is not tripping when you close the breaker. You should now be able to check for 12v at the wiper switch, and check if the voltage carries on to the motor when you turn on the switch. once you verify that power is going through the switch, leave it on and check for power at the wiper. If you have power there, you have to now check the ground circuit from the wiper to the ground bus. Switch the multimeter to ohms and put one lead on the ground wire at the wiper, and the other lead where it attaches to the bus. It should show a low resistance, if it shows infinite resistence then you have an open ground.
It may not be an electrical problem though. Sometimes salt water spray gets into the area where the wiper shaft goes through the whindshield frame. The water evaporates and leaves the salt behind, which will stick to the shaft and cause it to seize up. This is often a death knell for the motor. Hope this helps

 

[Daveroo]

Many thanks Gungadin. I will give that a try tomorrow night and see what results I get. I'll post up my results so all can share in the knowledge.

 

[Hoochiebob]

a simple voltage reading across the two leads to the wiper will suffice. if voltage is present and within tolerable values (12.6 to 9.0 volts) your wiper motor is bad. The readings should be taken as close as possible to the wiper to eliminate a bad fuse, connection or switch. As the motor brushes wear, the resultant carbon powder can deposit inthe inner workings and effectively stop the magnetic action from turning the motor. You need to rule out all other devices in the circuit first. Continuity checks ie: ohms/resistance checks may not uncover this problem. Best to do it on DC volts with power applied.
Keep us informed!

 

[Daveroo]

OK, I finally had time to tackle this problem. I checked the readings with the multimeter and zero both before and after the breaker! So I worked back by taking apart my console and looking at the electrical at the switch. One of the wires had popped off the connector because they had used a connector which was too small for the gauge of wire at the switch. Bought a new connector for larger gauge and the problem was solved! Thanks for the advice above.