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My heater blower fan isn't working so I went to look at the heater fuse under the dash. When I went to look at the fuse I saw a black wire with a spade terminal unconnected. I am not sure if I inadvertently disconnected it when I moved the wires to see the fuses. The little ignition block on the fuse panel is empty. Does anyone know where this goes? Should I just tape the end and leave it alone? I have added a picture showing the location and source of the unconnected wire. I placed black electrical tape around the wire so it would stand out. Maybe someone with electrical knowledge can tell me if and where this wire needs to be connected. My car is a 1972 350 with an automatic transmission, no emissions, no air, power steering and manual disc brakes. Thank you.
Last edited by Miccar; Oct 20, 2024 at 06:55 AM.
Reason: Add Picture
Being unsure of it I would probably wrap it in electrical tape to prevent any accidental shorting. I see that your accessory spots on the fuse block are being used by something someone installed. A bit of heat shrink could offer a lot of protection in the connections at the Fuse Block.
Where does the Black wire with the spade originate? I would follow it up and see where it goes. Being black is supposed to be a ground wire but be careful checking it's it has voltage present.
My all time favorite electrical tool is a device called a Power-Probe and it saves me a lot of time working on a Corvette's Electrical system. It lets you apply either battery voltage or battery ground at the tip by simply rolling a rocker switch built into the tool. It also lets you start at the window motor or any electrical part and test to see if it works when powered up. A very useful tool!
I tracked the wire back and it came from a wiring harness in the engine compartment near the lower driver firewall. I put electrical tape over the terminal for now. I started the car and checked out everything. Everything works except my heater fan. The only other issue I always had with my car is that when it is in gear you can start the car. I am the only driver of the car so it's just something I know not to do. Thanks for the reply.
The only other issue I always had with my car is that when it is in gear you can start the car. I am the only driver of the car so it's just something I know not to do. Thanks for the reply.
The disconnected plug with the Purple wire and Purple w/white tracer should be for your clutch neutral safety switch.
The switch it connects to is close by on the clutch pedal arm.
The only other issue I always had with my car is that when it is in gear you can start the car.
Just FYI, in your pic, the open two-wire connector with the purple wires is for the clutch safety switch (manual trans cars). The wiring harness has the circuit wires for both transmission types and just doesn't use the un-needed one.
Starting in any gear is likely a neutral safety switch issue. The switch is connected to the base of the shift lever and may be merely disconnected or broken. Not a particularly tough job but the metal shift console plate needs to be removed to access it.
Thanks for the replies. I taped up the terminal and everything seems fine after starting the car, with the exception of the heater fan not working and the neutral safety switch issue. The car will be put away in a few weeks and not driven often till then. Will I cause any damage leaving the wire there with the terminal taped up, until I get this checked out with the fan issue next year? I only have a couple of drives this season left and I want to make sure I don't start a fire or something.
Thanks for the replies. I taped up the terminal and everything seems fine after starting the car, with the exception of the heater fan not working and the neutral safety switch issue. The car will be put away in a few weeks and not driven often till then. Will I cause any damage leaving the wire there with the terminal taped up, until I get this checked out with the fan issue next year? I only have a couple of drives this season left and I want to make sure I don't start a fire or something.
Is there a spade on the engine side?
Do all of your gauges and radio work?
I tried to look under the dash of my '72 (auto trans) but don't see a single black wire. Because it has a spade, I'm thinking it has pulled out of a plastic connector that has multiple wires in it. The black wires I can find in this area are:
the TCS relay connector which is 3 wires wide with a drop-down wire [ – – – _ ] with the far left being the black wire.
the horn turn signal connector which is a long 11-hole wire connector with the #2 and #4 from left being black.
On the engine side, do you have a TCS wire connector on the transmission itself? (assuming you have the TH400)
Thank you for the reply 67. The radio, horn and turn signals work, but I didn't check out the instrument gauges. I will check them out tomorrow morning. I don't know anything about the TCS. I do know any emissions related stuff was removed from the car long ago. Are there any issues or problems leaving the wire disconnected if it is TCS related? Would the car experience any issues?
I checked all the gauges and the turn signals and they work, but my horn does not work now. Can you shoot me a picture of where the wire would connect for the horn. I believe I see the big plastic connector it has 10 wires attached but the second terminal is empty on the top and bottom of the plug. I don't want to plug it in the wrong terminal.
The horn now works. I placed a tire wire around the horn relayyesterday to secure it a little better and it pulled one of the plugs loose. I connected the plug better and now the horn works. I am taking the car to my mechanic next Monday to check the non working fan blower and the unconnected black wire. Thanks for the help guys.
Help Unconnected Black Wire
