I am using a 1984 Mazda pickup wiper motor, switch, and intermittent relay in my roadster (basically an all 1981 Ford F-150 wiring harness and system). Before fabricating the wiper mounting brackets last spring I bench tested the wiper motor and it seemed to spin okay. Last week I finally got around to hooking up the installed motor and now it does not run.
I uploaded the Mazda wiring diagram here but the quality is not that great. http://hotrodders.com/gallery/showphoto.php/photo/21307/size/big/cat/500/page/1
If you can't make it out you can go here (autozone) and click on Figure 12 http://www.autozone.com/servlet/UiB..._us/0900823d/80/20/77/19/0900823d80207719.jsp
I have taken the motor back out of the car to test and inspect and discovered one immediate situation which makes me very curious. The case on the motor is highly magnetized...at all times (note picture below). If you pull the case apart and remove the armature, neither the armature windings or the case by itself is magnatized. But when you attempt to re-assemble, there is a huge magnetic draw between the case and the armature windings. This seems odd to me so I wanted to bounce it off the experts.
If this is indeed suspect, I'm wondering if it could have occured during the fabrication process. I had to weld in the brackets for the motor with the motor installed. Is it possible that by welding fairly close to the motor I did something to mess of the polarity of the motor windings? And if so, is there a possible solution?
The other thing that makes me suspect is that when I put my tester on the switch and motor I get continuity from the hot wire going into motor all the way out of the motor and to the switch and the the ground wire coming off the switch. I can also get continuity in some (but not all) switch positions from the hot-in wire through the motor and out through the case.
If I hook the motor, switch and intermittent relay up as shown in the diagram, and put my voltage tester on it, I show 13 volts on the meter but the motor does not turn.
I did a site search on wiper problems and found this thread helpful http://hotrodders.com/forum/windshield-wiper-motor-83341.html?highlight=windshield+wiper+motor
regarding the theory etc. I should also point out that according to Doc, the ground off the wiper switch would normally go to the ignition switch in order to complete the ground (I'm assuming this is so the wipers would only work in the run position). For the sake of my testing, I am running this wire direct to chassis ground.
I uploaded the Mazda wiring diagram here but the quality is not that great. http://hotrodders.com/gallery/showphoto.php/photo/21307/size/big/cat/500/page/1
If you can't make it out you can go here (autozone) and click on Figure 12 http://www.autozone.com/servlet/UiB..._us/0900823d/80/20/77/19/0900823d80207719.jsp
I have taken the motor back out of the car to test and inspect and discovered one immediate situation which makes me very curious. The case on the motor is highly magnetized...at all times (note picture below). If you pull the case apart and remove the armature, neither the armature windings or the case by itself is magnatized. But when you attempt to re-assemble, there is a huge magnetic draw between the case and the armature windings. This seems odd to me so I wanted to bounce it off the experts.
If this is indeed suspect, I'm wondering if it could have occured during the fabrication process. I had to weld in the brackets for the motor with the motor installed. Is it possible that by welding fairly close to the motor I did something to mess of the polarity of the motor windings? And if so, is there a possible solution?
The other thing that makes me suspect is that when I put my tester on the switch and motor I get continuity from the hot wire going into motor all the way out of the motor and to the switch and the the ground wire coming off the switch. I can also get continuity in some (but not all) switch positions from the hot-in wire through the motor and out through the case.
If I hook the motor, switch and intermittent relay up as shown in the diagram, and put my voltage tester on it, I show 13 volts on the meter but the motor does not turn.
I did a site search on wiper problems and found this thread helpful http://hotrodders.com/forum/windshield-wiper-motor-83341.html?highlight=windshield+wiper+motor
regarding the theory etc. I should also point out that according to Doc, the ground off the wiper switch would normally go to the ignition switch in order to complete the ground (I'm assuming this is so the wipers would only work in the run position). For the sake of my testing, I am running this wire direct to chassis ground.