Radio wiring 1974 FJ40

[BlueMarblePA]

I need some help with wiring.

I have several wires in the back of the radio. Antenna is obvious. Two grey wires go to the speaker in the glove box.

Then I have three wires which look appropriate for the radio. Unfortunately, though, it seems they are always on.
I tested the red wire which is connected to red/blue and it is always on even without key in ignition.
I tested the yellow wire and it is also always on also without key in ignition.
The black seems to be a ground.

I thought one of these would turn on only with the key turned to accessory. If this is not the case and I need to get a new wire to be key on only, does anybody have a picture of the fuse box location for this?

 

[mrboatman]

You need to trace the wires out see were they connect to. Then insure the yellow is connected to a 12v constant source, the red should go to a 12v ignition on or acc only source. Then do a continuity check on the black to insure it is connected to a good ground source.
JP

 

[BlueMarblePA]

Looking at the wiring diagram, it looks like the radio and windshield wipers share same circuit.

When I try to trace the red which is butt connected to red/blue, I am visually blocked by darkness behind the dash. Should I be doing this with some. Kind of tool? Ohm meter? @mrboatman

 

[ToyotaMatt]

U will need a illuminated Test Light like this


i upgraded mine Snap-On one to a LED bulb from the dimmer incandescent


but u dont need anything fancy , just a $5 special from pep boyz will do

 

[BlueMarblePA]

I found that the yellow wire runs over the steering wheel to a white and taps into a white and blue wire near the fuse panel. Will have to research but it is obviously something that is always on

The black wire simply goes to a screw on the dash and is thus grounded.

The red becomes blue red and heads up the dash to a wiring loom with some aftermarket white tape. Hard to understand what is happening there

 

[mrboatman]

The white/blue comes from alt to ammeter then taps of to fuse block and continues to starter which connects to + battery cable. It will be hot all of the time. I would not recommend a tap off of this wire. Get constant 12v from constant 12v on fuse block. Use a volt meter or test light to find a 12v ignition power from the fuse block. On this wiring diagram it looks like your radio should use the ( L ) wiper wire coming from fuse block. http://www.globalsoftware-inc.com/coolerman/fj40/schematics/FJ40/1974FJ40/HaynesFJ401974.jpg If you blow it up it is easer to read.
JP

 

[ToyotaMatt]

the white w/blue tracer stripe as @mrboatman mentions is a constant HOT or B+ on all the time regardless of the ignition get position


make sure u Dis-connect your Positive battery terminal when Repairing the PO's BS , Messing with these HOT B+ wires