Help diagnosing Master Window circuit? 1999 LX (1 Viewer)

[shtbrwn86]

Pretty sure there is an issue with the wiring.

• All other door window switches work.
• Power lock switch from passenger door works.
• Replaced the switch, no change.
• NOTHING on the master switch works. Door lock, nor none of the doors.
• SOMETIMES the switch will work, but 19/20 it won't do anything.

I just don't know how to read the manual on this and hoping someone can clarify the testing procedure below.

Test 1: Multimeter positive to pin 9 and multimeter negative to body ground for continuity
Test 2: MM+ to pin 1 and MM+ to ground

and on and on down the list...

 

[dbfw]

Yes, and switching your multimeter between measuring resistance (or continuity of your meter has that function - mine does and will give an audible beep) to check continuity and volts DC to check voltage as specified by the manual.

If you're checking continuity using the resistance (ohms) function on your meter, you're looking for a very low value. High readings or OL, open circuit, etc. will indicate no continuity.

Volts DC will either auto-range or have various scales you can set to, this will essentially move the decimal point.

 

[shtbrwn86]

Yes, and switching your multimeter between measuring resistance (or continuity of your meter has that function - mine does and will give an audible beep) to check continuity and volts DC to check voltage as specified by the manual.

If you're checking continuity using the resistance (ohms) function on your meter, you're looking for a very low value. High readings or OL, open circuit, etc. will indicate no continuity.

Volts DC will either auto-range or have various scales you can set to, this will essentially move the decimal point.

I put my meter on continuity. It gives me a tone when there is continuity which I tested on a spare wire I had. Reads 0 and I get a tone.

Test 1: Pin 9 and ground and nothing.
Test 2: Pin 1 and ground and no voltage reading (set to 20v on the meter)
Test 4: Pin 3 to ground and nothing.

Not even sure how to go about this now!? Am I going to have to take the harness apart to try and find a short or frayed wire somewhere?

 

[dbfw]

I put my meter on continuity. It gives me a tone when there is continuity which I tested on a spare wire I had. Reads 0 and I get a tone.

Test 1: Pin 9 and ground and nothing.
Test 2: Pin 1 and ground and no voltage reading (set to 20v on the meter)
Test 4: Pin 3 to ground and nothing.

Not even sure how to go about this now!? Am I going to have to take the harness apart to try and find a short or frayed wire somewhere?

Well in some ways this might be easy, your tests so far suggest there is no ground at the connector. That would explain why the subsequent tests failed, they all need a good ground reference.

If it were me, I’d try to find out where the other end of that harness terminates and test the ground pin at that end. If you have a good ground there, you can be reasonably sure there is a break in the wire somewhere between those two points, likely at the hinge where it flexes.

Another thing you might try if you have a Toyota repair wire is to de-pin the ground from the connector, and run a temporary jumper to a known good ground, plug it back in and see if your window works.

But, the lack of ground and intermittent nature of the problem suggests a bad connection or broken wire somewhere between the switch and it’s next termination point.

 

[gnob]

the wre is probably broken in the section between the door and A pillar

 

[shtbrwn86]

Well in some ways this might be easy, your tests so far suggest there is no ground at the connector. That would explain why the subsequent tests failed, they all need a good ground reference.

If it were me, I’d try to find out where the other end of that harness terminates and test the ground pin at that end. If you have a good ground there, you can be reasonably sure there is a break in the wire somewhere between those two points, likely at the hinge where it flexes.

Another thing you might try if you have a Toyota repair wire is to de-pin the ground from the connector, and run a temporary jumper to a known good ground, plug it back in and see if your window works.

But, the lack of ground and intermittent nature of the problem suggests a bad connection or broken wire somewhere between the switch and it’s next termination point.

Yeah I do have a spare repair wire from when I wired up my stereo harness, but I think it would be easier to just trace that ground wire back to where it plugs in and see if there's a good ground there.

 

[shtbrwn86]

the wre is probably broken in the section between the door and A pillar

I mean that's what I think is probably the issue, but is that common? I can't imagine it would break in there. The harness is pretty well protected. And if it is a broken wire I guess I just clip it and what, put one of those solder butt connecters on? That harness seems like a pain to get into but it's also a pain having no working windows (and no working A/C). Makes the truck almost undriveable in the summer.

 

[dbfw]

Yeah I do have a spare repair wire from when I wired up my stereo harness, but I think it would be easier to just trace that ground wire back to where it plugs in and see if there's a good ground there.

Yep, I would start there for sure! Hopefully it’s good at that end and you can narrow your efforts to a small section of harness.

If you do find a break, I’d try to make the splice closer to one connector or another so your repaired area isn’t in the same spot getting stressed that broke. My lower tailgate wiring broke over the winter and I lost the reverse lights, I haven’t heard too much about the door harness doing that but it’s certainly possible.

If there’s been any water ingress into one side or the other of that harness that could be causing a high resistance connection too, but I suspect whatever the cause will reveal itself once you start tracing and testing to see how far you have to go to get a good ground.

 

[shtbrwn86]

I searched and searched before posting, but then I came across this post today... Sounds exactly like the issue I am having. I've already taken the door off and now I am going to pull the harness. Fun.

Power window master switch not working - can't close window

Hi, the power window switch panel on the driver side has stopped working on my 2001 Cruiser. And to make things worse, the driver window was down and I cannot close it. None of the switches work, can't control any window, the central locking system or switch to disable window control. All other...

forum.ih8mud.com

 

[OffRoadRN]

I’m having an issue with my master circuit. All of the windows work but the door lock unlocks and auto relooks all of the doors.

 

[shtbrwn86]

I think I found the problem lol I am assuming that severed white wire is the ground... Shocked it worked at all! Must just have needed to touch just right!
Open to suggestions on how to repair the severed wire. Normally I would use those heat shrink solder connectors but you need enough length to splice it.

Also, what about the two wires that are nicked but not broken? Can I just wrap them up in tesa tape?

 

[dbfw]

If you have time, I’d go buy some new same gauge wire, cut a length long enough to make the splices in a fixed area of the harness at both ends, not at the hinge where it broke.

In other words, cut it farther back on both sides of the break and splice it somewhere inside the door and inside the A pillar or wherever it doesn’t flex at the hinge for the longest term repair.

You can hopefully tape the new wire to the old on each end where it’s broken and use the old wires to pull the new one through. If you can, I’d splice all 3 that show signs of stress.

Looks just like my lower tailgate wiring when it broke at the hinge, the wiring is starting to get old and brittle on these trucks.

 

[shtbrwn86]

If you have time, I’d go buy some new same gauge wire, cut a length long enough to make the splices in a fixed area of the harness at both ends, not at the hinge where it broke.

In other words, cut it farther back on both sides of the break and splice it somewhere inside the door and inside the A pillar or wherever it doesn’t flex at the hinge for the longest term repair.

You can hopefully tape the new wire to the old on each end where it’s broken and use the old wires to pull the new one through. If you can, I’d splice all 3 that show signs of stress.

Looks just like my lower tailgate wiring when it broke at the hinge, the wiring is starting to get old and brittle on these trucks.

Went to the junk yard and grabbed a door harness from a similar year Tundra for free. Looks to have most of the same wires so it should work out fine, although I was really hoping to keep the colors the same but one of them doesn’t match. Oh well! Thanks for the suggestion. Should work well.

 

[shtbrwn86]

Used the idea @dbfw suggested above. Got some new wire of the same gauge, cut the old wire on one end, taped it to the new wire and pulled the new wire through. This gave me more room to splice those wires together with a heat-shrink solder connector. It's also puts the connections inside the door and inside the vehicle.

Connected the battery back up, hooked up the switch and it works!!! Even when the door is opened!

Additionally, I think this is why my driver door speaker kept cutting out.... due to faulty wires.

 

[dbfw]

Right on! I'm glad that all worked out and nice repair. I think I need to do similar soon, my driver door speaker is sometimes intermittent and I think the wire must be partially broken at the hinge on mine too.

 

[shtbrwn86]

Right on! I'm glad that all worked out and nice repair. I think I need to do similar soon, my driver door speaker is sometimes intermittent and I think the wire must be partially broken at the hinge on mine too.

FYI if you need some wires and don't want to go to the junkyard I can mail you some. I took a big harness out of a Tundra so I have a lot.

 

[tahoejoe]

Going through this now. Driver door speakers not working.
Pulled back the rubber conduit to door and was greeted to this.
Count at least 4 wires severed and multiple more on the way.
Also, corrosion inside one of the orange connectors to that wire loom.

 

[dbfw]

Nice, I'm 99% sure this is why my driver door speaker is intermittent, but I'm waiting for something else to stop working before I tear into it. Ever wonder how many flex cycles these wires have been through in 20+ years and hundreds of thousands of miles?

 

[tahoejoe]

Back of the envelope calculation
23 years x 365 days/year * 10 times door uses per day ~= 84 thousand door openings and closings

 

[shtbrwn86]

Back of the envelope calculation
23 years x 365 days/year * 10 times door uses per day ~= 84 thousand door openings and closings

That is premature failure and completely unacceptable. I thought these were built to last!