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5 Star Rising

Electrical help needed with unknown wires after dash removal

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So I restored my dash in my early 240z. I had took pictures before unplugging wiring but some how they got deleted off my phone. I know, should have labeled them. Also I'm dealing with a slight wiring hack job from the PO.

 

He cut and taped up wires under the dash and installed a after market fuse block to fit bladed fuses kind of cool but not sure how important these taped up wires are, obviously they went some where at one time unless some were just used for factory options that my car didn't come with.  

 

I will also say that I'm bringing the interior back to stock as much as I can. The PO had a fabricated metal plate cut to size and mounted it over where the map light, vents and entire face sat. Now I'm installing the stock components back, and attaching heater pull cables and wiring.  A little bit of a guessing game.

 

I found a 1970 wiring schematic but it is a little hard to follow with some of these random wires.

 

Does anyone know where this harness plugs in the picture below? Also where do the other 5 wires go?

3 are blue, 2 are white with one white wire having a black stripe.

2018-04-26 18.32.43.jpg

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If no one else chimes in, I'll take s look at my documentation tomorrow.  My recollection is that blues wires in the dash are often associated with the heating and cooling systems.

 

Those leads on the steering column appear to be factory original, so the FSM should show you exactly what they're connected to.

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2 hours ago, jhm said:

If no one else chimes in, I'll take s look at my documentation tomorrow.  My recollection is that blues wires in the dash are often associated with the heating and cooling systems.

 

Those leads on the steering column appear to be factory original, so the FSM should show you exactly what they're connected to.

This is what I got off the internet. If you stare at it long enough, you may begin to see purple elephants. Ha.   Is there another FSM schematic that shows where you are better on the drawing? Like "these are the wires under the steering wheel. Red goes to blue ect"

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Yeah, those "complete vehicle" schematics have their uses sometimes; but they can also be a nightmare.  Here's the only 240 body electrical FSM I have; it's for a '73.  May help you at least partially.  That 3-pronged female plug may be for power antenna (see page 4 on the attached). 

 

Have you checked  http://www.xenonzcar.com/s30/fsm.html?  This is the best source for Z car electrical schematics online that I know of.  Download EVERYTHING you might ever need....the website comes and goes over time; and you never know when it might disappear completely.

 

Good luck with it.

BE Body Electrical.pdf

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Thanks JHM. I believe I had that FSM downloaded somewhere before but I downloaded again now..and that Body Electrical link you sent is awesome but its still a bit hard to determine the single wires that are cut.

 

At this point I am going to keep searching the net for close-up pictures of 240 wiring and maybe I could piece it together. Took the day off work today which is rare, hoping to make some good progress today on the old Z. Including some body work. Summer is coming.  

 

Had this car sitting in my garage for 2.5 years and been working on it when I could. Time to get her in the paint shop, registered, and on the road by this summer. Cant wait.

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Happy to help.

 

WRT the unidentified cut wires, I would try testing them for continuity between the cut ends and the same-colored pin connectors at the big junction block in the passenger footwell.  Once you've found the correct wire/pin location on the junction block, you can use the FSM data to nail down the what the cut wire was for.  Sounds tedious, but really shouldn't take long once you get going.

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Ugh. So now I have no brake lights, rear flashers or rear turn signals. They worked fine before I removed the dash. I do have tail lights though. Been reading posts about this same issue and following the troubleshooting info given.

 

I have 12v at the stop fuse, 12v at the hazard switch (green/yellow), 12v at the Stop switch on one side, 12v leaving the stop switch when the brake pedal is pressed, 12v flowing up to the TS switch on yellow green and 12v coming back through the harness on white/red and white black and making it though the harness plug. Where does it flow after the TS switch? (Harness plugs then tail lights)?

 

I should mention I had replaced all my bulbs in the car with LEDs. How ever my new Led brake lights worked before removing the dash. I also had my hands in the rear of the car and removed both tail light units so I could seal them to the car, all I did was unplug the harness sockets with the bulbs still in them and lay them on the rear carpet. I didn't mess with any ground wires. It almost sounds like a ground issue to me but stumped.

 

I have 2 new LED flashers on order because the stock flashers won't work with my new LEDs. This day has been a bust. Open to any suggestions. I have the FSM.

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Disregard that last post I found the brake light problem. As a ex-mechanic and current splicing technicIan for the phone company I got a little clever or so I thought.  I used a wire tone generator  and placed "tone" on the harness of one of my brake light socket power leads, on the other end at the connection block above right kick panel I was able to pick up my tone with a tone wand amplifier probe.

 

I found that my tone stopped in that area and didn't make it to the correct wires on the TS switch or Hazard switch. I found that I had plugged in the wrong 3 prong plugs together that had the same plug. That's what I get for being slightly portly and not being able to see exactly what I was plugging in down there. Plugged the correct harness together and low and behold the brake light's and signals now light. I'm sure I will be on here tomorrow asking for more advice as I screw something else up or get stuck. I still need to trace those wires in the radio area tomorrow and see why they were cut and if needed.

 

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Posted (edited)
On 4/26/2018 at 8:41 PM, 5 Star Rising said:

maybe someone could identify where these wires connect under the steering wheel

I have the same problem with my steering column wire harness.  Had a pictures of the installed wires from the last time I disconnected them but now they're gone and I need them again.  From what I remember previously, some or all of those wires change colors at the connections. 

 

What we need is for some helpful soul to take pictures of his harness with the individual wires separated apart so we can identify them.  I found a couple of pictures on Google Images but none were clear enough for me to identify which wire was which.

 

edit:  there are a few here:  http://240z.jeromio.com/ac.html but my color vision is poor making that much difficult for me....

Edited by rossman

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9 hours ago, rossman said:

I have the same problem with my steering column wire harness.  Had a pictures of the installed wires from the last time I disconnected them but now they're gone and I need them again.  From what I remember previously, some or all of those wires change colors at the connections. 

 

What we need is for some helpful soul to take pictures of his harness with the individual wires separated apart so we can identify them.  I found a couple of pictures on Google Images but none were clear enough for me to identify which wire was which.

 

edit:  there are a few here:  http://240z.jeromio.com/ac.html but my color vision is poor making that much difficult for me....

Hope this helps. Not sure what year your car is, but this is on my early 71.

20180428_135132.jpg

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Posted (edited)

Slowly but surely making progress with this electrical mess in the radio area..so far I've got my map light and aftermarket stereo and power antenna working and wired.  But I did notice a few things that are not wired and are not working.

 

 I noticed that my windshield wipers are not working, to be honest I'm not sure if they ever did or at least I have never checked them.. Is there wiring that flows through the radio area that could be disconnected causing my wipers not to work? Or does that wiring route in a different area of the car? Tomorrow I can isolate and test the wiper motor some how, I might have a spare motor. The wiper fluid motor turns on when pushing the switch button in.

 

Also PO removed the rear window defroster switch from the console and installed another metal plate in its place. I found a factory switch and cover and installed it in the console how ever I have the 2 wires (Red) and (Green/Blue) coming off the switch stubbed up behind the radio and no where to plug them. Where the heck do they go?

 

I also have 2 wires hanging down from the dash harness behind the radio (Red) and (Green/White) not sure where they go as well, but I get 12v off the (Green/White) wire when I turn on the parking lights. Where the heck do these go? Following the FSM but hard to pin point where they go. Any help would be appreciated.

 

Bummed, clock doesnt seem to work either, ran power and ground to it direct and shes dead.

Edited by 5 Star Rising

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Posted (edited)

Were you able to download all the FSM docs you needed?

 

The wiper wiring runs from the combo switch, through the dash harness, to the wiper relay in the passenger footwell....it should not have any connections in the area of the radio.  There is a plug on the firewall inside the engine compartment which can become loose and/or corroded, causing the wipers to fail.

 

Hope this helps.

Edited by jhm

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Posted (edited)

I had checked the wiper motor harness at the fire wall last night before coming in for the night. It was a little corroded, i cleaned it and plugged it back in but no wipers. I went inside and turned on the switch and then back out to the firewall and moved the harness in and out and back n forth but the wiper motor did not budge.

 

I noticed when I had the switch off I had no power on any prong of the harness, but when I turned the switch on I had  12v power to one prong on the harness. Not sure how the power flows to this motor, I will try the FSM I have to better understand it.

 

PO had a bad switch assembly where the headlights didn't work.  I bought another switch off a guy who said the switch was for sale "but never tested".. lights worked fine but just now getting around to checking wiper motor circuit and I hope I didn't buy a bunk switch.

 

Also do the wires from the rear window defroster switch run up into the radio area and attach somewhere?

Edited by 5 Star Rising

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Current flows to the wiper motor through the wiper relay on the relay panel in the passenger footwell.  Relay could be bad, but I would test it before replacing.

 

The wiper motor could also be bad.  Try applying 12v directly to the motor to test.  The wiper mechanism may also be frozen, which would prevent the wipers from working, but they can be cleaned up and lubed pretty easily.

 

Yes, the switch for the rear defroster is typically located in the center console, under the radio.

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You may want to go through all of the dash wiring and make a wire list in a notebook or excel spread sheet (see example).  Basically what you need to do is document the wiring for current and future needs.

 

You can use address labels that you number and cut to fit the wire.  Loop the label around the wire and press the ends together. Take pictures after labeling and write down details in your spread sheet. Be sure to note what the wire does when energized. If you number a wire and don't know what it does, leave the function blank on the spread sheet and study the wire until you know what it does and then document it in the spread sheet.  

 

On my first 72 240Z, the PO cut/modified all of the engine bay wires. Using the above approach I corrected the wiring back to original function. From this point on I could identify every wire without a schematic.

 

The attached wire list was for my V8  conversion. For each wire in the list I applied power and noted on the spread sheet what happened at each position on the ignition switch/other switches before disturbing any of the wiring.

240z Wiring Tag Numbers Table.xls

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1 hour ago, jhm said:

Current flows to the wiper motor through the wiper relay on the relay panel in the passenger footwell.  Relay could be bad, but I would test it before replacing.

 

The wiper motor could also be bad.  Try applying 12v directly to the motor to test.  The wiper mechanism may also be frozen, which would prevent the wipers from working, but they can be cleaned up and lubed pretty easily.

 

Yes, the switch for the rear defroster is typically located in the center console, under the radio.

 

Do you know where to apply 12v on the wiper motor harness? I am about to dive into the wiper motor challenge. I didn't mention before that yesterday I went on a wild goose chase with no reverse lights but found the issue was the PO put his own connector on one of the reverse switch leads which had popped off happy to fix that. 

 

Actually on my early Z the rear window defroster switch is located on the rear of the console but the wires run up into the radio area under the dash and I cannot seem to find where they plug in. Wonder if my harness has a place for them. I am adding this switch where the PO had removed it. So close to closing everything up under the dash and moving onto body work.

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1 hour ago, Miles said:

You may want to go through all of the dash wiring and make a wire list in a notebook or excel spread sheet (see example).  Basically what you need to do is document the wiring for current and future needs.

 

You can use address labels that you number and cut to fit the wire.  Loop the label around the wire and press the ends together. Take pictures after labeling and write down details in your spread sheet. Be sure to note what the wire does when energized. If you number a wire and don't know what it does, leave the function blank on the spread sheet and study the wire until you know what it does and then document it in the spread sheet.  

 

On my first 72 240Z, the PO cut/modified all of the engine bay wires. Using the above approach I corrected the wiring back to original function. From this point on I could identify every wire without a schematic.

 

The attached wire list was for my V8  conversion. For each wire in the list I applied power and noted on the spread sheet what happened at each position on the ignition switch/other switches before disturbing any of the wiring.

240z Wiring Tag Numbers Table.xls

I actually did what you said yesterday besides making a spread sheet. I wrote them all down and tested each one then labeled them with masking tape. This is how I was able to connect my power antenna, radio and map light. Also checking each circuit by pulling the fuse to see my test light turn off to see which circuit that wire was on. 

 

Just need to figure out where the rear defroster switch wires plug into and why my wipers dont work.

 

Oh and might take apart my clock and apply synthetic clock oil to the mechanical mechanism and see if it will come back to life. Then the interior is pretty much done for now.

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21 minutes ago, 5 Star Rising said:

Wires from my rear defroster switch going up under dash/radio area. Where do I plug these?

20180429_132308-1.jpg

Think   just found the power wire for my rear window defrost switch. I actually ran continuity from my meter from the back window red black wire and I picked up the continuity under the dash on the red black wire..duh...  

 

now I just need to find out where the green wire off the switch attaches to.. On the rear window the other wire is black and when I run continuity it seems as if that wire is going to chassis ground so I'm wondering if I could just tie the green wire off the switch to any ground source and be good

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Update***  Forget the rear defroster system... Just found out the switch is bad in my console, not to mention the vertical defroster wires in my back window glass are pretty chowed any ways. Looks like this switch is just going to be for looks in the center console. Oh well dont plan on driving my car in the dead of winter anyway or leaving it over night somewhere out side for the window to get super fogged up. Now onto the wiper motor issue.

20180429_134555.jpg

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Sorry guys I'm bouncing all over the place with things today with the electric system and PO hacking. So I'm wondering where the wiper motor relay is located on my early 71. I checked the passenger kick panel area and only see a hazard flasher and one other relay that looks like a wiper relay but has different wires going to it that are not on the FSM. I will recheck but I dont think there was any other similar plugs that I could have plugged in wrong but maybe.. damn.

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