[cboy]

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/showph...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/UiBr...3d80207719.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/windshie...ld+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.

[302 Z28]

There are a lot of myths about welding involving automobiles. One is that if you weld on a frame with an engine in it all the ring gaps will line up. This is totally ridiculous. It is certainly possible to mess up electrical and electronic devices by welding on or near them though. I suspect that is what happened to the motor. As far as magnetized, isn't that a permanent magnet motor?

Vince

[red65mustang]

deleted post because the ss board is not on the motor

[cboy]

Originally Posted by 302/Z28

As far as magnetized, isn't that a permanent magnet motor?

I don't know the answer to that but attached to the inside the case, on opposite sides, there are two pieces that would appear to be magnets (they are solid looking). However, when you remove the windings armature, the case and these two pieces no longer exhibit a magnetic force. But when you insert the windings between these two pieces, there is a very strong force...so much so that it is a bit difficult to get the pieces assembled. This may be totally normal for this sort of motor...I've just never had one apart before so it struck me as curious.

Regarding red65mustangs response: Is this intermittent ss control board in the motor iteself or in the intermittent relay? The reason I ask is that only the motor was installed when I did the welding, not the intermittent relay. Also, there doesn't appear to be anything inside this motor/case that looks damaged or even very complicated for that matter. Just your nomal contacts and brushes (which appear to be in good shape).

[red65mustang]

cboy, deleting my post above, the board wasn't on the motor when you welded....you didn't fry it

sorry, don't know how to test a Toyota wiper motor, call a dealership?

[cboy]

Originally Posted by red65mustang

cboy, deleting my post above, the board wasn't on the motor when you welded....you didn't fry it

Well, at least your post eliminated a possible culprit. So it was still helpful.

[cboy]

The following is from a post by Doc (see above thread link) along with some questions it raised for me regarding how to test the wiper motor.

Doc: "You will note, The power wire (Yellow Orange or Black Yellow) from the fuse runs DIRECTLY to the wiper motor, and is "Hot in Run at all times" , The Switch Provides grounds to the various speeds..( Light blue for high, Black for low speed)

If your trying to wire power through the switch, (the most common oops..) that's bass ackwards , as opposed to the way it works, which is different from the rest of the world..Ground is wired through the switch and power is constant to the motor any time the Ignition switch is on.

With the motor mounted, and the power wire on the motor (Yellow Orange) , and the key on, Jump the Light blue to any good ground, It should run at High speed."

******
So my question is, why do you need to have the key on in the above test? If you are jumping the light blue wire direct to ground, and the purpose of the wire to the ignition switch is to provide ground (not hot), isn't it redundant to run the light blue wire to ground? Or is the purpose of the above test to determine if your ignition ground is, in fact, working properly? [Note: edit added after a little more thinking - I assume the reason for turning the switch on is only to provide power to the hot side of the motor - not to provide a ground through the ignition switch, correct? The ground thru the ignition is still redundant.

I would guess I'm missing something here...but shouldn't any wiper motor be able to be tested simply by hooking the incoming hot wire on the wiper motor to a hot source and then grounding either the hi or low wire exiting the wiper motor? Or is there something unique about wiper motors that requires more than one ground. (Actually, since the case is also grounded when it is mounted, it would appear they could be THREE grounds).

If I conduct the above test (simple hot to motor and grounding either the hi or low exit wire) my motor doesn't spin. It DOES however produce a spark when I touch the hot off the battery to the hot wire to the motor or a 12 volt reading on a voltmeter - so it does seem to be running to ground - just not spinning the motor.

[docvette]

Originally Posted by cboy

The following is from a post by Doc (see above thread link) along with some questions it raised for me regarding how to test the wiper motor.

Doc: "You will note, The power wire (Yellow Orange or Black Yellow) from the fuse runs DIRECTLY to the wiper motor, and is "Hot in Run at all times" , The Switch Provides grounds to the various speeds..( Light blue for high, Black for low speed)

If your trying to wire power through the switch, (the most common oops..) that's bass ackwards , as opposed to the way it works, which is different from the rest of the world..Ground is wired through the switch and power is constant to the motor any time the Ignition switch is on.

With the motor mounted, and the power wire on the motor (Yellow Orange) , and the key on, Jump the Light blue to any good ground, It should run at High speed."

******
So my question is, why do you need to have the key on in the above test? If you are jumping the light blue wire direct to ground, and the purpose of the wire to the ignition switch is to provide ground (not hot), isn't it redundant to run the light blue wire to ground? Or is the purpose of the above test to determine if your ignition ground is, in fact, working properly? [Note: edit added after a little more thinking - I assume the reason for turning the switch on is only to provide power to the hot side of the motor - not to provide a ground through the ignition switch, correct? The ground thru the ignition is still redundant.

I would guess I'm missing something here...but shouldn't any wiper motor be able to be tested simply by hooking the incoming hot wire on the wiper motor to a hot source and then grounding either the hi or low wire exiting the wiper motor? Or is there something unique about wiper motors that requires more than one ground. (Actually, since the case is also grounded when it is mounted, it would appear they could be THREE grounds).

If I conduct the above test (simple hot to motor and grounding either the hi or low exit wire) my motor doesn't spin. It DOES however produce a spark when I touch the hot off the battery to the hot wire to the motor or a 12 volt reading on a voltmeter - so it does seem to be running to ground - just not spinning the motor.

Doc here,

WHEN Refering to GM types of wiper systems: The reason you need the key on , Is because the wiper motor in it's stock habitat is wired to the Switched , fused side of the Ignition buss..to provide power to the hot side of the motor in run..(the same reason it won't run when the key is off on stock wiring.)

The Delay, the Low, the High speed functions are simply nothing more than "Taps" so to speak, from the OTHER SIDE of the motor winding to Ground, to provide speed change..

Since the wiper motor has power constantly in run, all it needs is the other side of the motor winding to ground to complete the circuit.

You can, in fact, run power to the power terminal on the wiper motor, and ground to any of the three terminals on the wiper motor to bench test it..

My reference was to the wiper motor in it's stock habitat, where it's simply easier to run ground to any of the three speed terminals on the plug..and just turn the key on rather than manhandle a second jumper wire.

The ignition Switch SHOULD not have any grounds on it at all. The speed switch movable contact is hardwired to ground.

If you have Power to the Main power terminal, and ground to ANY of the three wiper speed controls AND ground to the motor body, and it does not run, or produce a big spark, the motor is either bad, or the "Park" limit switch internal the motor is stuck or broken rotor locking the motor..

As for the magnetic attraction on the wiper motor case, if you pull that down , I'll bet you'll find two curved magnets mounted around the circumference of the inside of the winding body, I just check a few around here, and there is a minor magnetic attraction on them also, (different from yours though..Corvette types , flat and plastic covers..) That's probably normal.

Does that clear that up?

Doc

[cboy]

Originally Posted by docvette

If you have Power to the Main power terminal, and ground to ANY of the three wiper speed controls AND ground to the motor body, and it does not run, or produce a big spark, the motor is either bad, or the "Park" limit switch internal the motor is stuck or broken rotor locking the motor..

Can one get at the park limit switch in the event it is stuck? What does it look like and what exactly is it supposed to do?

[docvette]

Originally Posted by cboy

Can one get at the park limit switch in the event it is stuck? What does it look like and what exactly is it supposed to do?

Doc here,

The park limit switch is internal the wiper transmission and is a micro switch..

I suppose you could get to it..but at that point I think it would be easier to replace the whole unit then go bonkers trying to align up the gearing again ( a little too much, not enough..) so that park is actually full down actuated and span and all that is correct again..

More energy than I would expend on it..

Doc

[red65mustang]

cboy,
you used the wrong word, that is not a "intermittent" motor set up, it's a simple 3 speed motor,

agree with doc, get another from the yard, test it there

LOL, I was right for the wrong reason?...you did "fry it" while welding probably

[cboy]

Originally Posted by red65mustang

cboy,
you used the wrong word, that is not a "intermittent" motor set up, it's a simple 3 speed motor,

From what I'm looking at (the wiring diagram and the actual wiring), I'd have to conclude the system does have an intermittent feature. There is an external relay in the wire harness and it is identified as an "Intermittent Relay" on the wiring and diagram.

Regarding replacement (as opposed to repair) - it's not good news. We don't have much in the way of "junk yards" around where I live. Most have turned into scrap metal yards - and they don't keep many cars around to scavenge parts any more. The one yard that still does have cars doesn't have any old Mazda pickups. The only yard that I've found that could get the part...is getting it from another supplier, not their own yard, so the price is very high. From CarQuest its $130 and from the yard it's $80. Also, on the internet I'm finding prices in the $80 plus range. Seems steep to me.

[schnitz]

Dewey, I just checked at Car-part.com for a wiper motor for a B2200 Mazda truck. $25. Thing is though, they ask is it's equiped with am/fm or am/ no radio. Could it possibly be interference from another system in the rat?

Most of the time, this site helps me find the oddball stuff.


In a while, Chet.

[cboy]

Originally Posted by schnitz

Dewey, I just checked at Car-part.com for a wiper motor for a B2200 Mazda truck. $25.

Shoot, your post was about 3 minutes too late. I just ordered a new one line from Advance Auto. Funny, the Car-part.com web site never came up in my google searches...and your are right, it's a good site, exactly what I was looking for. I'm assuming one has to contact these junk yards directly to work out payment and shipping but still, for the prices they are listing, it sounds like a good alternative.

Anyhow, I bit the bullet already so I'm just going to stick with the new unit. But I'm adding Car-part to my bookmarks for future use.

Dewey

[schnitz]

Dratt... Yeah, you need to call and set up parts pickup-deliver stuff, but that really seems like a decent place to shop. Oh well, a day late and a dollar short....


in a while, Chet.