Stereo Install Wiring Help, 74 914 2.0 Options

[OKN929]

Hello 914 World! I'm a new owner of a 914 that long overdue. Got so much great info from here and been working on it slowly and it's been amazing all that 914World members help each other!
Now I got my dash restored and the gauges all looking nice and new with a few upgrades and need help with installing a stereo.

My 914 has an antenna but no stereo wires, can someone please tell me which wires I would need to tap into to get my stereo installed correctly.

Thank all in advance!!!

[technicalninja]

Those two threads are for serious amplified systems and may be more than the OP needs.

They are definitely worth reading but I'm guessing the OP has modern simple head unit that is not going to require serious power feeds.

Modern head unit has 3 main feeds into it.

Black- this goes to a good ground. I'll use a under dash sheet metal screw/bolt, clean up the fastener/hole of paint and rust. Install a proper star washer between an eyelet that I crimp/solder onto black wire. A bit of silicon grease (corrosion protection) and that's done.

Yellow-memory: battery power. Can come from fuse box. Find a circuit that is hot at all times and use a tap to install. This is a small amperage load.

Red-power wire: Hot in ignition "ON" only. This can be a much higher amperage load (depending on the internal amps in the head unit) and needs to come from a higher rated fuse in the fuse box. This wire is wise to have a second fuse on and some radios come with a fuse in this wire already.
Avoid power sources that also run ignition or the fuel injection as the radio can do funky things to those systems.
A noise cancelling capacitor is sometimes a requirement on this leg.
I'd want the feed from a 20 amp or larger fuse if i can get it. Most are fused 10 amps in their included fuse. leave the original fuse (if it has one) in it.


Xtra feeds/outputs
Inputs:
Orange/orange with stripe is often the lighting circuit for the radio and sometimes can feed off of the gauge lighting circuit. This can allow the lights in the head unit to dim with the lights in the dash via the dash rheostat. This is a small amperage load. This feed works great with modern cars, but early dash lighting (before 1990) sometimes did the dimming portion in a different way. Don't kill yourself to make the radio lights work with the dash lights if it gives you fits.
Hook it to power source you used for red lead should give you max bright when radio on.

Outputs:
Blue- this is a "remote on" signal from the radio. It can initiate power to an amp. it can run a modern power antenna. This wire goes hot after the radio fires up and starts sending a 12v signal. You may not need it at all. Early power antennas have multiple ways they worked as well. Some cars had individual switch on the dash for the antenna. If your 40-year-old power antenna will not work, you will have to figure out a work around (can be difficult!) or replace it with a more modern unit that triggers exactly like a modern amplifier. The remote on wire on both the amp and the modern antenna will be blue as well.
Many amps/antenna/other remote on devices can be daisy chained to this feed.

Those are the inputs/outputs in a nutshell.

The speakers should be self-explanatory.
Watch polarity on the speaker wires closely. Look at the instructions carefully. Sometimes the striped color is the positive and sometimes it's the ground.
Make sure to hook the speakers up correctly.