Front wipers not responding

[rasouth]

Hi everyone!
I have a '96 Explorer 4.0 that I discovered that the front wipers and washer do not work. I live in SoCal so it is not frozen with ice or blades are stuck to windshield and since it is SoCal there is not much rain right now. I just happened to turn my wipers on and nothing happened! I have checked the fuses with my Ohm meter and they were good. I checked the fuse box and I am getting power to the fuses. I checked the relays under the hood and they seem to be okay. I switched the relay for the horn and wipers and horn worked with all three relays (Wiper run, Wiper hi/low. and horn). I tried to test the wiring harness and I am getting constant power when key is on and tried to test the other wires, (bl/o, w, blk, red, bl, blk) and I was not getting much of a reading from the rest, with or without switch being in run or intermittent. I was testing with a resistance setting on my meter. ( I was following someone else's instructions on how to test the harness). I came to the conclusion that my switch (MFS) was bad and pulled it out and tested it. The book I have gave instructions on what prongs to test with my meter and I came up with a negative on the switch so I replaced it. No luck! What the book did not tell me is that I needed my meter on not on continuity but on 20K or even 200K resistance setting. My old switch is good.
I am at the end of my rope trying to figure this out. If switch is good, fuses and relays are good, then what? I even went as far to take motor off but I am not sure how to test the motor. I know I was getting constant power but nothing out of the others. The two black wires in the harness are grounds and as far as I can tell they are grounded. I believe that the front and rear washers work off the same fuse and rear washer works.
I would really appreciate any help with testing motor and harness and fixing this problem

 

[97-5.0]

Take the end cap off the turn signal, undo the little star screw inside, take off end and look inside, there will be 2 little contact arms that touch on the circuit board in there, clean all the old dirty grease out, slightly bend the arms so the make contact harder against the circuit board, if you have dielectric grease put very little in or nothing, put back togeather and your good to go, good luck

 

[rasouth]

I tried that on the old one with no luck. As stated above I replaced the MFS with a new one. I do not believe the problem lies with the switch.

 

[J_C]

You can test power to the motor by measuring for it with a multimeter on ~20V DC range mode, when it's supposed to be on of course.

You can test the motor itself by jumpering 12V to it direct from the battery or an alternate, medium-current capable 12VDC power source.

However if you measure power getting to it, you can use that power to test the motor too, no need to rig up something else. If it's getting 12V but not spinning then it's bad unless it's just a fouled connector contact.

 

[rasouth]

Thanks for the input. I do have constant power coming into the motor on the Red wire when key is in Run position. There are two Black wires I presume are grounds and a light blue wire I think is the Park for wiper blades. That leaves two more wires: A blue with orange stripe and a white wire. From what I can find those are the wiper high and wiper low wires.
To test motor would I need to supply motor with constant power and ground and then touch power to either the high or low wires to get motor to work?
I have already eliminated switch, fuses and relays as not being the problem but would like to test motor to be sure.

 

[J_C]

On the diagram I have, one black is Park Sense and the other black is ground. Gray/light-blue is Wiper Speed Control. Blue & orange are "interval/delay wash in" and yellow & white is "brake/run relay control".

I hope I'm reading this right because it looks like you'd jumper red to white for low speed or red to dark-blue/orange for high speed.

 

[rasouth]

Thanks for the diagram. I've been looking for one. This will help a lot.

 

[rasouth]

I tested the motor and it ran, so it's not the motor. I pulled relay in Power Dist Box and ran a continuity test for the White and Blue/Orange wire and got continuity, so I'm guessing the harness to the motor is okay, (no broken wires or terminals.) I pulled out the switch on the steering column, again, and it tested out okay. Relays seem okay (I switched them with the horn relay and all three worked.) It seems that the signal is not getting from switch to the PDB. Fuse #16 for wiper is good and I'm getting power to the fuse in the fuse panel, sooo...
I am at wits end on what is wrong. Anybody have an idea? Do wires from switch go straight to PDB or do they go somewhere else and then to PDM? How would I test wiring harness from switch to PDM?
Luckily it's not raining here in SoCal, just 110 degrees and I'm working outside.

 

[J_C]

The wires from the switch go to the GEM module. How did you test the switch? It looks like based on the switch position, you should measure a resistance between the Pink/Yellow wire and Gray/Red wire that varies from (nearly) 0 ohms on high speed, to over 100 ohms near max delay. With a worn switch the reading could drift higher.

If you are confident that your switch is working, you can test without the GEM involved by grounding the yellow/white wire, and the gray/light-blue wire which should close both relays. Being methodical, when you ground the yellow/white, you should then measure 12V on the wiper hi-lo relay pin 3. You can pull the relay out and measure that socket contact. With the relay installed then you should measure 12V on the white wire to the motor.

That should put the motor in low speed. Grounding the gray/light blue should put it in high speed, then you should measure 12V on the dark-blue/orange wire at the motor. I wrote 12V but possibly closer to 14.4V if the engine (alternator) is running.

If grounding those causes the motor to operate and you're sure the switch is good, then I suspect your GEM has failed.

 

[rasouth]

I bought a new switch and before hooking it up I tested it according to the manual; checked the ohm's between pin 13 and 14 with wiper switch in off, interval and high position and got a reading of 46.3k, 11.3k and 0, respectfully, which, according to the manual is a properly working switch.
My next question is, where is the GEM located? And how and where do I find those wires?
BTW...Thank you for all of this help.

 

[J_C]

I don't know about differences between model years but it should be behind the radio.

How where do you find what wires? They are the colors shown on the diagram, on the plug to it and unless there is a connector in between, stay the same to the relevant sensor, switch, relay, etc. Consult that diagram I posted.

 

[rasouth]

The plot thickens!! I had a speaker stop working and pulled out the radio. I was looking at the wires trying to figure out if there was a loose wire or plug on the backside of radio. I disconnected the radio and all the connectors to the surround; rear wiper control knob, cig lighter, 4-wheel drive knob, etc. I wonder if the GEM got unplugged with all my rooting around back there.
Does the GEM have anything to do with the radio ?

 

[J_C]

If the GEM is unplugged you'd have more problems than just the wipers. See if your one-touch-down driver's window function works. It depends on the GEM. Then again, I've see instances where a GEM was plugged in and both the window and wiper functions failed but the GEM otherwise still worked.

As for the radio I don't recall, there may be some battery saver circuit associated with it that the GEM controls.

Either way it's certainly a good idea to pull the radio and check the wiring and plugs.

 

[rasouth]

I haven't noticed any other problems. The door locks work, windows work, interior light works along with some other bells and whistles. The only other thing that doesn't work is the front washer. It worked occasionally before, like the contacts inside were dirty but I replaced the switch as stated above so that shouldn't be the case now.
I will try your suggestion to bypass GEM.

 

[rasouth]

What do you mean by grounding out the yellow/white wire and gray/light blue wire? Touch them together? Touch them to a ground? Touch them to power? I have pulled radio out and can see no loose wires on GEM.

 

[J_C]

Place a jumper wire between the yellow/white wire (currently going from Wiper Run Relay pin 2 -to- GEM pin 19) and ground. Ground can be any non-painted object connected to the metal chassis like a bolt head or whatever. That should close the circuit on the wiper run relay so the wipers turn on in low mode.

If that doesn't work, you'll need to start measuring voltages along that path on the diagram I posted. If that does work, the GEM isn't ground it like it should when you use the switch. You do not need to use the switch when jumpering it, when the red wire has 12V the wipers should come on as soon as it's jumpered. In other words keys in ignition on aux or run.

You can also, leaving that jumper in place, connect the gray & light blue wire to ground which should switch the wipers from low mode to high.

However this 2nd jumper doesn't necessarily tell me anything more (see below). I mean that if the motor works jumpering the yellow/white to ground and the switch is good, then the only possibilities remaining that I see are a bad wire, bad connector, or the GEM is damaged.

I forget which relays you mentioned that you swapped but this is assuming that the Wiper HI-Low relay was one swapped and confirmed to work. However if it was only confirmed to work in an energized state in place of another relay, the first jumper test puts power through it in the unenergized state (as shown on the diagram) so that would rule out a bad contact in the relay to pin 4.

In other words, if the first jumper test does not work, if the wipers don't come on in low, you might still want to jumper gray /light blue to ground to see if wipers come on in high mode, again leaving the other jumper in place still.

One other possibility is that I'm wasting your time because my diagram isn't right for a '96, but if you're seeing all the same wire colors then it probably is.

 

[rasouth]

Are you saying to pull wiper run relay and probe the number 2 pin slot and then to ground? Or from GEM number 19 with relay in place? I am getting what you are getting at, just unsure where to connect probe. I disconnected the harness from GEM and tried to probe #19 but couldn't tell if I had a good ground, and then after turning key off my blinker relay kept clicking until I plugged harness back in.

 

[J_C]

From GEM 19 position on the harness connector, with the relay in place. If there's space in the back of the connector, I would just stick a probe tip in there instead of unplugging the GEM. I don't know what unexpected things might happen without the GEM connected.

You could set a multimeter in current measurement mode (~200mA range should be plenty) and then when you see the milliamps flowing, you now you're grounding the relay coil. With a helper you could also listen for the relay energizing click when that is done, but no need if the wipers start moving.

You can instead test by pulling a relay but that doesn't confirm the relay is working. In that case just pull the wiper hi-lo relay and jumper between the socket contacts corresponding to pin 1 and 3. However I wouldn't run the wiper motor long like this, just in case they cheaped out and used a higher gauge (thinner) red wire for that because normally it only carries enough current to power the relay coil, not the wiper motor. It's probably not an issue, probably all the same gauge wires but you really only need the wipers moving for a second to see that these parts of the circuit work.

 

[rasouth]

I thank you for all the help. I've rebuilt several cars in my time but most of them were older ones, built before computers. I'm okay with tearing down and rebuilding but not real good at diagnostics, especially newer cars.
I'm taking the day off from the wipers because it's about 108 here and I got a 1965 Mustang in the garage so I would have to work in the sun. Maybe later tonight.

 

[rasouth]

Just got done jumping yellow/white wire and motor worked. Bad GEM? I saw a GEM on eBay that said it came from same year, same model number, same number of doors... Pretty much the same all over. Okay to replace with that?