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subzali
10-27-2013, 10:00 PM
Calling electrical gurus.

Rear wiper operates on intermittent even when switch is turned off.

I checked the switch and didn't have continuity between pins 1,2,10, and 16 when switch was off.

So is it the relay or the wiper motor? Or should I check the switch again?

See attached pdf...

The relay side of the L-R wire is getting 12V when the wiper motor is disconnected. I think it's supposed to be 0? So if that's true that points to the relay.

Pins 1 and 4 of the wiper motor have continuity, about 20 ohms resistance. I think they are not supposed to have continuity at rest, so if that's true that points to the wiper motor.

Or maybe I'm reading something wrong? :confused:

Snowrun
10-28-2013, 09:32 AM
:thumb::wrench:I have the same issue and it drives me nuts. It would be nice to figure out what is causing it.

60wag
10-28-2013, 10:18 AM
Can you unplug the L-B connector between the switch and the relay and see if it still does intermittent?

subzali
10-28-2013, 11:51 AM
Can you unplug the L-B connector between the switch and the relay and see if it still does intermittent?

I was trying to figure out the ground path for the current, I'll see if I can just undo the L-B. I don't think I can but I might be able to get creative with alligator clips.

If it still operates in intermittent then it's gotta be the relay or the motor, if it stops then I need to look at the switch again.

subzali
10-28-2013, 02:06 PM
Just to keep the documentation in this thread, the L-B wire comes back up the harness through a connector (BR1) in the storage panel.

That connector also has:
-R-Y - Rear door courtesy light
-L-Y
-L-G - from rear wiper relay to switch for wiper ON function.
-W-B - ground for rear wiper motor and possibly other stuff (defogger, high stop light, door courtesy), so that needs to be connected.
-G-W - rear stop light
-Y
-B - rear window defogger

Have to identify what those go to and if having them unplugged will affect anything.

Might also see if BT1 would be a better place to unplug.
Wires in BT1:
-L-power to the wiper motor
-L-B-from rear wiper relay to switch
-L-G-from rear wiper relay to switch
-B/L-G-rear window defogger
-L-R-rear door lock
-L-W-rear door lock

Inukshuk
10-28-2013, 04:42 PM
Mine does not work at all and I will tackle it before winter sets in. I'll be following this thread

subzali
10-28-2013, 10:02 PM
Can you unplug the L-B connector between the switch and the relay and see if it still does intermittent?

I was trying to figure out the ground path for the current, I'll see if I can just undo the L-B. I don't think I can but I might be able to get creative with alligator clips.

If it still operates in intermittent then it's gotta be the relay or the motor, if it stops then I need to look at the switch again.

Okay, I disconnected BT1 and ran a jumper for the L wire. The wiper stopped working with the switch OFF (yay, I think I found the problem?). I switched it to ON and jumpered the L-G wires and it worked as designed.

Earlier I pulled the relay and tested it per BE-25 in the FSM. I think it tested out ok. The only thing I'm not sure of is this phrase in Step 3: "...check that the meter needle rises from 0 V to battery positive voltage within 6 to 10 seconds. If operation is not as specified, replace the relay."

The voltage rises to battery voltage almost immediately, not between 6 to 10 seconds. Think it's ok?

Going to check the switch again.

On a good note I busted out the epoxy and I think I fixed the shaky driver side mirror. So at least I'm making forward progress.

subzali
10-29-2013, 03:06 PM
I pulled apart the dash and checked the switch plug again. It appears fine. I need to get a better continuity tester though; my digital multimeter (set on ohms) kinda bounces around but then always lands on infinite resistance.

In fact, same thing happened last night when I was checking around the BR1 connector in the rear quarter panel. Unplugged, the L-B resistance to ground would bounce around and then land on infinite. It was doing some other weird things that I should confirm and document (got a test light today to do that), but I'm worried that the problem is in the wiring somewhere. I hope not. It's all in good shape, the fasteners, wiring, connectors, etc. no corrosion just a little dusty so I'm amazed there's a problem.

subzali
10-29-2013, 07:51 PM
Well I got a test light and the L-B isn't grounded with the switch off. So now I'm not sure what to do, feels like I have to start over.

subzali
10-29-2013, 10:31 PM
BR1 contains:
-L-B - from rear wiper relay to switch
-R-Y - Rear door courtesy light
-L-Y - stops at connector
-G - from rear wiper relay to switch for wiper ON function
-W-B - ground for rear wiper motor and possibly other stuff (defogger, high stop light, door courtesy)
-G-W - rear stop light
-Y - nothing?
-B - rear window defogger

BR1 forward to the switch:
-L-B - NO path to ground
-R-Y - NO path to ground
-L-Y - NO path to ground
-G - NO path to ground.
-W-B - path to ground
-G-W - path to ground
-Y - path to ground
-B - path to ground

BR1 back to hatch:
-L-B - NO path to ground
-R-Y - NO path to ground
-G - NO path to ground
-W-B - NO path to ground
-G-W - NO path to ground
-Y - NO path to ground
-B - NO path to ground

BR2 contains:
-L-W - rear door lock
-L-Y - rear defogger
-L - power to rear wiper relay and motor
-L-R - rear door lock

BR2 forward to switch:
-L-W - path to ground
-L-Y - NO path to ground
-L - path to ground
-L-R - path to ground

BR2 back to hatch:
-L-W - NO path to ground
-L-Y - NO path to ground
-L - NO path to ground
-L-R - NO path to ground

BT1 contains:
-L-R - rear door lock
-B/L-G - rear window defogger
-L-G - from rear wiper relay to switch
-L-B - from rear wiper relay to switch
-L - power to the wiper motor
-L-W - rear door lock

BT1 back:
-L-R - NO path to ground
-B - path to ground
-L-G - NO path to ground
-L-B - NO path to ground
-L - NO path to ground
-L-W - NO path to ground

BT1 forward (BR1, BR2 unplugged):
-L-R - NO path to ground
-B/L-G - NO path to ground
-L-G - NO path to ground
-L-B - NO path to ground
-L - NO path to ground
-L-W - NO path to ground

BT1 forward (BR1 plugged in, BR2 unplugged):
-L-R - NO path to ground
-B/L-G - NO path to ground
-L-G - NO path to ground
-L-B - NO path to ground
-L - NO path to ground
-L-W - NO path to ground

BT1 forward (BR1 unplugged, BR2 plugged in):
-L-R - path to ground
-B/L-G - NO path to ground
-L-G - NO path to ground
-L-B - NO path to ground
-L - path to ground
-L-W - path to ground

BT1 forward (with BR1, BR2 plugged in):
-L-R - path to ground
-B - path to ground
-L-G - NO path to ground
-L-B - NO path to ground
-L - path to ground
-L-W - path to ground

Relay terminal back to switch (BR1, BR2 unplugged):
-L-B - NO path to ground
-L-W - NO path to ground
-L-R - NO path to ground
-L-G - NO path to ground
-L - NO path to ground

Relay terminal back to switch (BR2 unplugged, BR1 plugged in):
-L-B - NO path to ground
-L-W - NO path to ground
-L-R - NO path to ground
-L-G - NO path to ground
-L - NO path to ground

Relay terminal back to switch (BR1, BR2 plugged in):
-L-B - path to ground
-L-W - NO path to ground
-L-R - NO path to ground
-L-G - NO path to ground
-L - path to ground

subzali
10-30-2013, 07:38 AM
If anyone with a working rear wiper has time and wants to help, could I ask you to perform the test on BE-25 for intermittent operation for me and post up your results (specifically see if the voltage rises right away or if it's delayed by 6-10 seconds)? You have to take off the rear hatch handle (2 M8 screws), and pop off the plastic trim piece. Then unscrew 1 M8 screw that holds on the relay and unplug the relay. Then take it to your battery with a multimeter and some test leads and alligator clips. Takes 10-15 minutes.

In the post above, the wiring has me spooked. L-B from the relay has no path to ground unless I plug in BR2 in the quarter panel area. Here's the thing. L-B doesn't run through BR2. It runs through BR1, at which point it also doesn't have a path to ground. I think L-B might be shorting with L possibly in the upper hatch area. But I would like to confirm my relay operation before tearing in that deep.

60wag
10-30-2013, 09:46 AM
Without digging into your test results, my guess is that the relay is triggering the intermittent function without the required ground input from L-B. Maybe the input transistor is failing? If you can swap the relay, it might solve the entire issue. Or if you really want to diagnose it, you could pull the L-B input up to +12v to see if that shuts it off.

subzali
10-30-2013, 09:48 AM
If someone wanted to swap relays with me that would be awesome too :thumb:

Working on pricing for a new relay, but I'm thinking I won't like the price :(

Jacket
10-30-2013, 10:06 AM
You could try a bone yard or part out for better pricing.

blkprj80
10-31-2013, 07:24 AM
This might help. Hopefully yours isn't toast like his.
http://forum.ih8mud.com/80-series-tech/463273-fzj80-rear-wiper-relay-cross-reference.html

subzali
10-31-2013, 09:47 AM
This might help. Hopefully yours isn't toast like his.
http://forum.ih8mud.com/80-series-tech/463273-fzj80-rear-wiper-relay-cross-reference.html

Thanks for that link, I hadn't seen that one yet.

I cracked mine open this morning and it looks perfectly brand new. How reliable are transistors? They are solid state so I would assume they are usually not a concern.

subzali
11-01-2013, 07:22 PM
I got a used relay today from classic cruisers in salida. Plugged it in and wiper acts the same, stuck on intermittent. So unless two relays which don't appear to have failed have failed exactly the same way, I'm ruling the relay out.

60wag
11-01-2013, 08:10 PM
Hmmm. Does it still do intermittent with L-B unplugged?

subzali
11-01-2013, 08:50 PM
It stops if I unplug the L-B at the BT1 connector in the rear hatch. I have some more diagnostics to do, I have a suspicion that the wiring is doing something funky at the top of the rear hatch, between BT1 and BR1 in the quarter panel.

subzali
11-02-2013, 10:28 PM
Hmmm. Does it still do intermittent with L-B unplugged?

L-B has 220 ohms of resistance to the bolt on the jack holder (ground) with the switch off. With the switch on intermittent there are 25 ohms. As a comparison, L-G has infinite resistance when the switch is off and 3.5 ohms with the switch on. This is measuring from the plug at the relay.

The body side of L-B at connector BR1 has 327 ohms with the switch off, 3.5 ohms with the switch on intermittent. It has infinite resistance in the hatch direction. L-G has infinite resistance with the switch off and 3.5 ohms with the switch on.

subzali
11-02-2013, 10:35 PM
The pins in the switch have infinite resistance when switch is off and 1.4 ohms when switch is in intermittent.

60wag
11-04-2013, 05:32 AM
I've never dug into the wiring bundle going through the top of the hatch on the 80 but it does sound like you have eliminated the switch and the relay as the problem. I did repair a washer hose in the top of the hatch on a 60 once. That was way more work than it should have been.