Mystery Wires (stereo, maybe?), wiring |
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Mystery Wires (stereo, maybe?), wiring |
avocadotom |
Aug 8 2020, 06:17 PM
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#1
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Newbie Group: Members Posts: 5 Joined: 17-September 19 From: Pittsburgh, PA Member No.: 23,469 Region Association: None |
I am in the (hopefully) last stages of assembling my ‘72 914 and I’m hoping to install a stereo.
There are two mystery wires coming out of the hole where the stereo would be, although they do not appear to be the negative and positive wires (although I didn’t check if they independently have power to them). Any idea what they might be? Backstory: I bought this 914 disassembled by a previous owner and I’m new to 914s, so it’s been a journey... Attached thumbnail(s) |
BPic |
Aug 8 2020, 06:44 PM
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#2
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Member Group: Members Posts: 341 Joined: 5-February 18 From: Miami, Florida Member No.: 21,864 Region Association: South East States |
Can’t tell in the photo. What color are they?
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bbrock |
Aug 8 2020, 06:54 PM
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#3
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914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
It isn't for a stereo because those are not built in to the harness. Stereos had a separate harness. The brown wire is a ground. My guess is it is for the fan controls. There should be a tab on the slider mechanism to connect to ground. Can't tell what color the other wire is.
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sholman5 |
Aug 8 2020, 09:06 PM
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#4
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Kraut burner Group: Members Posts: 189 Joined: 11-September 16 From: Ormond beach, Fl. Member No.: 20,391 Region Association: South East States |
Check the wiring diagram for the fresh air heater control slider.
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avocadotom |
Aug 12 2020, 10:44 PM
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#5
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Newbie Group: Members Posts: 5 Joined: 17-September 19 From: Pittsburgh, PA Member No.: 23,469 Region Association: None |
Thanks all, I’ll do just that!
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76-914 |
Aug 13 2020, 09:46 AM
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#6
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Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,490 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California |
It isn't for a stereo because those are not built in to the harness. Stereos had a separate harness. The brown wire is a ground. My guess is it is for the fan controls. There should be a tab on the slider mechanism to connect to ground. Can't tell what color the other wire is. Probably yellow. Yellow morphs to brown after 50 years. Peel back that insulation a tad to reveal the color. (IMG:style_emoticons/default/beerchug.gif) |
avocadotom |
Aug 17 2020, 09:31 AM
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#7
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Newbie Group: Members Posts: 5 Joined: 17-September 19 From: Pittsburgh, PA Member No.: 23,469 Region Association: None |
Ha! I will totally peel back the wires to see what colors they were originally.
I did a little more digging into this last night and the smaller wire is brown with a white line, and it has 12 V to it with the ignition on. The larger "brown" wire does not have any voltage. I don't think it's a ground wire either, because when I connect the two wires through a multimeter, I don't see any voltage. FWIW, the fresh air fan works, so it's hooked up to something. And to make matters more confusing, there are similar wires (larger gauge brown, smaller gauge brown and white) in the harness as well that ARE hooked up to the fresh air controls. You can somewhat see them in the picture below. |
Junebug |
Aug 17 2020, 12:05 PM
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#8
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Newbie Group: Members Posts: 20 Joined: 7-May 15 From: East Bay Area NorCal Member No.: 18,713 Region Association: Northern California |
only brown/white wire I see on schematic are: Parking brake contact , Brake warning Light, Parking brake contact in-line diode, Steering column switch to horn relay and Right side door switch (push button) FWIW
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lierofox |
Aug 17 2020, 12:07 PM
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#9
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Member Group: Members Posts: 256 Joined: 23-June 15 From: Paso Robles, CA Member No.: 18,880 Region Association: Southern California |
I wonder if the brown wire with white tracer is for the seat belt warning light.
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bbrock |
Aug 17 2020, 12:15 PM
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#10
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914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
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scallyk9 |
Aug 17 2020, 02:36 PM
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#11
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Member Group: Members Posts: 318 Joined: 16-October 16 From: Port Orchard, WA, USA Member No.: 20,499 Region Association: Pacific Northwest |
Not sure with a '72 model year 914 but on both of my 1974s, brown with white tracer wires are connected to the door contact switches on each side, meeting at the tunnel and going to the under passenger seat door open buzzer relay from which a single brown/white tracer wire heads up to the interior cabin light. My recollection is fuzzy but earlier models had a different system for the door contact switches in each side's door jamb. I think they were hot which is what the red/white wire might be. This brown/white wire appears to be too short to reach over to the passenger front door jamb.
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bbrock |
Aug 17 2020, 03:11 PM
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#12
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914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
That's right. For factory wiring, solid brown is a ground and brown with white tracer is a switched ground. You are right, door switches, brake lever contact, interior light, etc. all have brown with white tracer because those are switched grounds meaning that the ground circuit isn't completed until a switch makes contact. If you test the voltage on one of those wires upstream of the first switch in the circuit, it is going to read hot because you are completing the ground circuit with your meter or test light. If you test on the other side of an open switch, you will get nothing.
The interior light is a good demo because it has both a brown and brwn/white wire attached. One position on the light switch closes contact to the solid brown ground connector and the light comes on. The opposite position closes contact to the switched ground but the ground circuit isn't completed until you open a door and close a contact on a door switch. This all may be interesting for understanding the theory behind the car wiring, but doesn't help with what that particular wire does. It also assumes a PO hasn't gotten creative with borrowing and splicing wire. |
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