Front Wipers on 2002 4.6L Explorer stopped working

[SiDziner]

My front windshield wipers stopped working on my 2002 4.6L eddie bauer explorer. The washer sprays.

I checked the fuse (#8) and it is good. I tested the run/park and high/low relays by putting them in the fog lamp relay position and verifying the fog lamps still worked. I checked the 5-pin harness that plugs into the wiper motor, and no pins have +12V no matter what position the wiper switch is in (low,high,intermittent,off).

I think there should be at least 2 pins on the motor harness at +12V if the wiper switch is set to low or high (the run pin, and either the low or high pin). If so, the problem is that the motor is not getting energized. Does that sound correct?

So, at this point, is it the multi-function switch?

thanks,
-g

 

[07gtman]

there is another fuse for the front wiper motor #21 30 amp. in the fuse box under the hood right behind the battery you will see a black box that would be it..

 

[SiDziner]

the owner's manual indicates #21 in the power distribution box is not used. The location does not have a fuse in it. Since the wipers worked before, and no fuse has been removed, I don't think that location is used for the wipers. Did you mean a different location than #21?

 

[SiDziner]

A little bit more information ... I did some experimenting, and I think I have convinced myself it is not the switch.

As I stated before, I did not measure +12V on any of the pins in the harness that connects to the motor. But I did notice a tiny voltage on some pins. I went down to the mV scale and found that the wiper switch makes tiny (but measurable) differences in voltage on the pins.

the 5 pins in the harness (wire color followed by what I think the signal is based on googling, which could be wrong)
1) light blue - wiper park switch input
2) red - power start/run
3) black - ground
4) white - low speed
5) dark blue/orange stripe - high speed

                             switch position
pin    off     int1    int2    int3    int4    int5    Lo      Hi
1      570mv   580mv   590mv   580mv   590mv   580mv   590mv   590mv
2      180mv   180mv   180mv   180mv   180mv   180mv   180mv   250mv
3      0 for all switch positions
4      same as pin 1
5      really noisy for all switch positions, but bouncing close to 0

so based on pins 1 and 2, each step of the switch has a measurable change in tested voltage at the harness. this makes me think that the switch is ok.

does my theory that the switch is ok sound right?
any ideas?
Possibly the GEM module?

 

[hlg99]

Had a similar issue with my wipers not working, I found that the ignition cylinder was worn and not returning all the way into the run position after starting. Problem has not come back since I replaced the cylinder.

 

[07gtman]

Ok lets make sure you have the right fuse...It would be the from looking at the fuse box under the hood behind the battery standing in front of the drivers side wheel. open the black box, From the top left corner 3 rows down and 3 fuses to the left. it has a window you can see right into the fuse..If there is not a fuse there try and put one the its place a 30 amp. you could take #22 its autolamp low beam and its a 30 amp that you can do a test with.. good luck

 

[SiDziner]

hlg99, thanks for the suggestion. that is a possibility but I don't think that is it.

07gtman, we are talking about the same fuse location. That location is empty on my explorer. You are referencing the 6th manual printing of the 2002 explorer. Mine is the 4th printing. I bought it new in 2002, so I know this is the manual that came with the explorer. I have verified that the 4th printing matches my explorer. e.g. the 4th printing indicates the #8 internal fuse controls the washer pump relays. The 6th printing indicates the #8 fuse is not used. When I pull the #8 fuse, the washer pumps no longer work.

I really need an interval wiper wiring diagram for an early 2002 explorer. (Anyone know where i can find one?) I have a wiring diagram for a 2001 explorer (attached here), but there are differences with the 2002 where it matters (hot in ACC or Run -> wiper run relay).

Based on the 2001 diagram, for the run relay, pins 2 and 5 should be hot when the switch is on. Pin 3 connects to the high/low relay. When the wipers are switched on, the GEM should pull pin 1 of the run relay to ground. This energizes the run relay and connects pin 3 to pin 5 (which should be hot because the key is on). +12V then runs to the high/low relay. Depending on the state of that relay, +12V is connected to either the high or low pin for the motor and it runs at the selected speed. I used my ohm meter to test out the connections from the run relay through the high/low relay to the motor harness.

With the key on, +12V is not present at any pin on the run relay or the high/low relay. I connected pin 3 of the run relay socket to +12V (essentially bypassing the relay so that it is always on), and as expected the wiper motor ran. The motor ran at low speed because the high/low relay connects the low speed motor wire if the relay is not energized.

So my problem is that I am not getting +12V at the relays.

In the 2001 diagram, the wipers and washers run off different fuses. However, based on the 2002 user manual, there is only 1 fuse used for the front wiper and both washers (fuse #8 in the internal panel). Both washers run fine. This means that power is getting through the #8 fuse to both washer relays, but power isn't getting to the front wiper relays.

So, I need the wiring diagram to tell me how the +12V coming out of the #8 fuse gets to the front wiper run and high/low relays, and the washer pumps. According to the manual, both washer relays are on the top of the internal fuse panel. So it looks like +12V is getting to the internal relays off the #8 fuse, but not the relays in the power distribution box, or pin #2 of the motor harness. I think when the motor is running, it connects pin #2 (+12V) of the motor harness to pin 1 of the harness which goes back to the GEM so it knows when the motor is running versus parked.

based on the 2001 diagram, there is a connector and a splice point (S163) that drives the 3 relay pins and the motor wiring harness that should be at +12V when the switch is on. I would like to see on the 2002 diagram where the washer relays pull off the +12V (probably before the connector since they are on the internal fuse panel).

So, does anyone have a 2002 explorer wiper wiring diagram? Or have any suggestions where to look for the connection problem?

 

[07gtman]

google this i cant seem to copy it... interval wiper wiring diagram for an early 2002 explorer

 

[SiDziner]

07gtman, ok ... i googled that, and i get lots of hits, but none that i have looked at so far are actually 2002 explorer wiper wiring diagrams. Can you be more specific?

 

[SiDziner]

Uhm ... found the problem.

This is the wiring harness coming through the firewall to the power distribution box. There are at least 2 broken wires (Red and Brown). I think the red is the +12V when key is on.

Any recommendations as to how to repair this? I can't even get my hands back there.

 

[07gtman]

was something in there chewing on wires?

 

[SiDziner]

No, it doesn't look like that to me. I guess the picture doesn't show it that well. It appears to me that there isn't enough support for the wiring harness, and it is really kinked in there. So there is a lot of downward force on the wires and a lot of lateral force on the wires at the point that the tape is wrapped around. If you look close, you can see where the insulation around the red wire has actually been separated about an inch above the fraying due to the downward force. I think the fraying is due to vibration against the edge of the tape over the last 17 years. I will try to get a better picture.

 

[07gtman]

there are 3-10mm bolts on the inside of the fender remove them. take out the battery, there is a vacuum line and a plug attached to the power distribution box, those can be removed to push the box forward to where the battery tray is now there is enough space to get to that spot.. still a tight spot though but i was able to do this in 20 mins though, i did not do any of the repair needed, i think it can be done.

 

[07gtman]

i see that all the wires in these trucks i have found to be tight, the ones in my mountaineer have very little slack in that spot i got my hand down in there there was very little room for a one handed wire stripper and maybe some crimp connectors tape them up and hope for the best ...good luck...keep me posted

 

[SiDziner]

I punted. I'm big, and a little clumsy, so I was concerned about tackling it. I didn't trust myself to get back there and not screw it up further. So I took it to a mechanic. He took care of it. It wasn't too expensive since I had already did all the troubleshooting. Wipers now work. Thanks everyone for the help.