bicycle_ben Posted December 15, 2008 Share Posted December 15, 2008 i peeked through the "manual" and didnt find anything that seemed to fit my problem. i am hoping someone here can help or point me in the right direction ive got an 81 gl wagon where a prior owner did some hack wiring in the poor thing. none of my fuses match what they were supposed to operate ... the starter motor was wired into the stereo ... i dont think the wiring to the back hatch is hot ... more importantly the windshild wipers dont work! when i picked the car up a week or so ago i checked to see that they worked and i didnt use them again till a day ago. when i turned them on they didnt move at all and a breaker or something tripped in the accessories wiring causing the heater blower to stop. when i turn the key off and then back on something re sets and the blower works again. i disconnected the wiper motor and then turned the wiper switches on and off to see if it would still kill the power to the blower. with the wiper motor un plugged the blower didnt get killed so i blamed the wiper motor. just for fun i used my multi meter to see how much juice the wiper motor was beeing supplyed. i got 3.6 something volts to one wire with the wipers on LOW and 3.6 to a different wire with the wipers on HIGH. i tried all sorts of wire/wiper settings/ground combinations to see if i would get more juice but i didnt. is my wiper motor supposed to run off of 3.6 volts or do i need to go looking for something gone wrong in my rats nest of wires? also i took the wiper motor apart and it looked good inside. it wasnt frozen up or anything but i dont know if its blown something i cant see so who knows... anyway , all the help i can get would be awesome! Quote Link to comment Share on other sites More sharing options...
Cougar Posted December 16, 2008 Share Posted December 16, 2008 The motor should have 12 volts going to it but you may have measured at a point that is beyond the input power. I think the speed switch changes how the motor coils are arranged; either in series or parallel. It appears that the motor is bad from what you stated so you may have to replace it. Quote Link to comment Share on other sites More sharing options...
bicycle_ben Posted December 16, 2008 Author Share Posted December 16, 2008 i tested the juice at the connection from the wiring harness to the wiper motor so i guess it really should be 12V. i un plugged the wiper motor and poked my multi meter into the plug. i guess i get to go hunting for shorted out wires today ... Quote Link to comment Share on other sites More sharing options...
Skip Posted December 16, 2008 Share Posted December 16, 2008 Howdy Ben, The Circuit Breaker part is a mystery. There is a CB inside the wiper motor wiring (locked wipers due to ice ect) but the car was not equiped with one from the factory for the blower. At any rate, I got out my 1981 Factory Sevice Manual (FSM) and looked up your wiper wiring system. Cougar is correct as usual, your wiper motor runs on 12 Vdc. At the wiper motor plug (unplugged) (the end connected to the car's harness) you should get these voltages. Note: the Black with Yellow tracer (BY) is the ground wire, do not go to frame of the wiper motor as it may be isolated for wiper parking control. It shows fuse # 7 as the wiper fuse. In all positions the Blue (L) wire is energized with + 12 V in reference to the BY wire. sw. off........L - -> BY = +12V sw on low....Green/Yellow - -> BY = +12V sw on high...Blue/Yellow --> BY = +12V Hope this helps with the trouble shooting. I will go into the parking position control if you need. Quote Link to comment Share on other sites More sharing options...
Cougar Posted December 16, 2008 Share Posted December 16, 2008 You stated in your first post that when you disconnected the wiper motor the blower worked ok when you turned the wiper switch on. To me this would seem to state that the wiring is ok. It is the motor that is the trouble since you isolated it except for one possibility. I suppose there could be a bad connection in the power lead to the blower relay control and wiper motor so when you turned on the wiper motor the voltage to the relay control for the blower didn't have enough voltage to activate the blower relay due to a bad power, or voltage drop, across a connection upstream. Skip, does your wiring diagram show the wiper motor and blower relay control circuit being tied to the same power connection? Quote Link to comment Share on other sites More sharing options...
Skip Posted December 16, 2008 Share Posted December 16, 2008 Glen, went looking for the fan power fuse and found first the wipers are fuse # 3 not # 7 as the troubleshooting diagram had labeled and the blower relay is powered by fuse # 1 but that is dependant on if there is AC fitted or not. Quote Link to comment Share on other sites More sharing options...
Cougar Posted December 16, 2008 Share Posted December 16, 2008 Thanks for the info Skip. So according to the manual there shouldn't be any power lead tie between the two systems but somehow there is. Perhaps then there has been some mods done, as the OP stated in his first posting. If that is the case then it may be best to try and rewire the the power leads like they should be. Quote Link to comment Share on other sites More sharing options...
Skip Posted December 16, 2008 Share Posted December 16, 2008 Glen, you are most welcome, I could not agree more with your assessment/statement. Quote Link to comment Share on other sites More sharing options...
bicycle_ben Posted December 17, 2008 Author Share Posted December 17, 2008 so i took the wiper motor off to play with it. i ran 12v to the fast and slow speed connections from the battery and grounded the motor case. i was able to get the motor to spin at both speeds. when i plugged the motor back into the wiring harness it didnt spin and still killed the heater fan then i thought hey maybe i can go from the fuse box to the motor with my own wires! ... motor didnt spin still killed the heater ... this to me means that something in the motor is bad even though it can still spin i could run my own wiring through a switch to the battery but the fact that its not making the factory wiring happy means to me that this could be a bad idea ... you know, setting my car on fire and what not Quote Link to comment Share on other sites More sharing options...
Cougar Posted December 19, 2008 Share Posted December 19, 2008 If you didn't notice a problem with the motor while it was working when you removed it from the circuit then perhaps the motor is ok. It would be nice to know what the current draw of the motor is while it is out of the car. I assume you have made sure the wiper arms are not jammed mechanically. It sounds like the wiper motor is wired in series with the blower circuit somehow. Quote Link to comment Share on other sites More sharing options...
bicycle_ben Posted December 19, 2008 Author Share Posted December 19, 2008 mechanically everything seemed to be in order so i just ran my own wires too and from the battery with an inline 15A fuse. i have OFF LOW and HIGH but dont quite understand exactly how the HOME and INT positions are to be wired. i assume that when you set it to OFF its supposed to run juce to one of the contacts on the gear inside the motor so that it spins till it gets to the HOME position and then shuts off. what i dont know is exactly how to wire that up because i wasnt able to get it to go HOME while playing with it out of the car. since i cant get HOME to work i cant really make INT work because im fairly sure that INT uses HOME and some little timer thing burred under my dash in a rats nest of wires.... oh well ive gotten good at just turning them off at the right time Quote Link to comment Share on other sites More sharing options...
Skip Posted December 19, 2008 Share Posted December 19, 2008 glad you have it working, the park position is simple with the diagram Thanks for all the help Glen (Cougar) Quote Link to comment Share on other sites More sharing options...
Cougar Posted December 21, 2008 Share Posted December 21, 2008 Just going by what I seem to remember I believe you are correct about constant power going to the Park lead of the motor. When the cam of the motor gets to the park position it opens the constant power connection to the motor. The dash power switch bypasses the Park power lead connection to the motor so it supplies power to the motor only until it is turned off. The Park power lead then takes over until it is opened by the cam and parks the wipers. For the intermittent position I think the switch supplies power to the module when that is selected but I would have to look at the diagram to be sure of that. Skip, Thanks for your help on this also. Glen Quote Link to comment Share on other sites More sharing options...
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